SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  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') 
WHERE 
  cscart_products_categories.product_id IN (
    114, 192, 136, 130, 128, 126, 131, 177, 
    186, 185, 179, 11, 172, 134, 135, 195
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00071

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "35.99"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "0.43"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 84,
            "rows_produced_per_join": 3,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "19.53",
              "eval_cost": "0.67",
              "prefix_cost": "20.20",
              "data_read_per_join": "8K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`pankajecarter_systemfour`.`cscart_categories`.`storefront_id` in (0,1)) and ((`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')))"
          }
        },
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "pankajecarter_systemfour.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 3,
            "rows_produced_per_join": 0,
            "filtered": "4.28",
            "index_condition": "(`pankajecarter_systemfour`.`cscart_products_categories`.`product_id` in (114,192,136,130,128,126,131,177,186,185,179,11,172,134,135,195))",
            "cost_info": {
              "read_cost": "13.34",
              "eval_cost": "0.09",
              "prefix_cost": "35.55",
              "data_read_per_join": "6"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
11 224M
114 243M
126 251M
128 251M
130 251M
131 209M
134 182M,179
135 179,182M
136 249M
172 199M
177 212M
179 212M
185 214M
186 214M
192 232M
195 232M