SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  products.amount, 
  descr1.product as product, 
  companies.company as company_name, 
  variation_group_products.group_id AS variation_group_id, 
  products.product_type, 
  products.parent_product_id, 
  descr1.full_description as full_description 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'en' 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
  INNER JOIN cscart_product_variation_group_products AS variation_group_products ON variation_group_products.product_id = products.product_id 
WHERE 
  1 
  AND companies.status IN ('A') 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND variation_group_products.group_id IN (21) 
  AND products.product_type != 'D' 
GROUP BY 
  products.product_id 
ORDER BY 
  NULL asc

Query time 0.00153

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "7.87"
    },
    "ordering_operation": {
      "using_filesort": false,
      "grouping_operation": {
        "using_temporary_table": true,
        "using_filesort": false,
        "nested_loop": [
          {
            "table": {
              "table_name": "variation_group_products",
              "access_type": "ref",
              "possible_keys": [
                "PRIMARY",
                "idx_group_id"
              ],
              "key": "idx_group_id",
              "used_key_parts": [
                "group_id"
              ],
              "key_length": "3",
              "ref": [
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 1,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "1.00",
                "eval_cost": "0.20",
                "prefix_cost": "1.20",
                "data_read_per_join": "16"
              },
              "used_columns": [
                "product_id",
                "group_id"
              ]
            }
          },
          {
            "table": {
              "table_name": "products",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "status"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "pankajecarter_systemfour.variation_group_products.product_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 0,
              "filtered": "89.52",
              "cost_info": {
                "read_cost": "1.00",
                "eval_cost": "0.18",
                "prefix_cost": "2.40",
                "data_read_per_join": "3K"
              },
              "used_columns": [
                "product_id",
                "product_type",
                "status",
                "company_id",
                "amount",
                "usergroup_ids",
                "parent_product_id"
              ],
              "attached_condition": "(((`pankajecarter_systemfour`.`products`.`usergroup_ids` = '') or find_in_set(0,`pankajecarter_systemfour`.`products`.`usergroup_ids`) or find_in_set(1,`pankajecarter_systemfour`.`products`.`usergroup_ids`)) and (`pankajecarter_systemfour`.`products`.`status` = 'A') and (`pankajecarter_systemfour`.`products`.`product_type` <> 'D'))"
            }
          },
          {
            "table": {
              "table_name": "companies",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "company_id"
              ],
              "key_length": "4",
              "ref": [
                "pankajecarter_systemfour.products.company_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 0,
              "filtered": "20.00",
              "cost_info": {
                "read_cost": "0.90",
                "eval_cost": "0.04",
                "prefix_cost": "3.47",
                "data_read_per_join": "1K"
              },
              "used_columns": [
                "company_id",
                "status",
                "company"
              ],
              "attached_condition": "(`pankajecarter_systemfour`.`companies`.`status` = 'A')"
            }
          },
          {
            "table": {
              "table_name": "products_categories",
              "access_type": "ref",
              "possible_keys": [
                "PRIMARY",
                "pt"
              ],
              "key": "pt",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "pankajecarter_systemfour.variation_group_products.product_id"
              ],
              "rows_examined_per_scan": 11,
              "rows_produced_per_join": 1,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "1.61",
                "eval_cost": "0.39",
                "prefix_cost": "5.48",
                "data_read_per_join": "31"
              },
              "used_columns": [
                "product_id",
                "category_id"
              ]
            }
          },
          {
            "table": {
              "table_name": "cscart_categories",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "c_status",
                "p_category_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "pankajecarter_systemfour.products_categories.category_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 0,
              "filtered": "5.00",
              "cost_info": {
                "read_cost": "1.97",
                "eval_cost": "0.02",
                "prefix_cost": "7.84",
                "data_read_per_join": "263"
              },
              "used_columns": [
                "category_id",
                "storefront_id",
                "usergroup_ids",
                "status"
              ],
              "attached_condition": "(((`pankajecarter_systemfour`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`pankajecarter_systemfour`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`pankajecarter_systemfour`.`cscart_categories`.`usergroup_ids`)) and (`pankajecarter_systemfour`.`cscart_categories`.`status` in ('A','H')) and (`pankajecarter_systemfour`.`cscart_categories`.`storefront_id` in (0,1)))"
            }
          },
          {
            "table": {
              "table_name": "descr1",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "product_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id",
                "lang_code"
              ],
              "key_length": "9",
              "ref": [
                "pankajecarter_systemfour.variation_group_products.product_id",
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 0,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.01",
                "eval_cost": "0.02",
                "prefix_cost": "7.87",
                "data_read_per_join": "460"
              },
              "used_columns": [
                "product_id",
                "lang_code",
                "product",
                "full_description"
              ]
            }
          }
        ]
      }
    }
  }
}

Result

product_id amount product company_name variation_group_id product_type parent_product_id full_description
149 1 8GB E Series Walkman Video MP3 CS-Cart 21 P 0 <p>Long lasting battery offering up to 50 hours of music or up to 10 hours of video playback, FM tuner, Karaoke mode, Clear Audio technologies, EX headphones, integrated mic and 2.0" LCD.</p>