SELECT 
  f.feature_id, 
  f.purpose, 
  p.product_id, 
  p.parent_product_id, 
  g.id, 
  g.code 
FROM 
  cscart_product_variation_group_features AS f 
  INNER JOIN cscart_product_variation_groups AS g ON f.group_id = g.id 
  INNER JOIN cscart_product_variation_group_products AS p ON f.group_id = p.group_id 
WHERE 
  p.product_id IN (
    185, 186, 187, 188, 189, 190, 191, 1, 5, 
    7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 
    18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 
    28, 29
  )

Query time 0.00072

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "146.07"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "p",
          "access_type": "ALL",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "rows_examined_per_scan": 61,
          "rows_produced_per_join": 31,
          "filtered": "52.46",
          "cost_info": {
            "read_cost": "7.99",
            "eval_cost": "6.40",
            "prefix_cost": "14.39",
            "data_read_per_join": "511"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ],
          "attached_condition": "(`pankajecarter_systemfour`.`p`.`product_id` in (185,186,187,188,189,190,191,1,5,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29))"
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "pankajecarter_systemfour.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 31,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "32.00",
            "eval_cost": "6.40",
            "prefix_cost": "52.79",
            "data_read_per_join": "12K"
          },
          "used_columns": [
            "id",
            "code"
          ]
        }
      },
      {
        "table": {
          "table_name": "f",
          "access_type": "ref",
          "possible_keys": [
            "idx_group_id"
          ],
          "key": "idx_group_id",
          "used_key_parts": [
            "group_id"
          ],
          "key_length": "3",
          "ref": [
            "pankajecarter_systemfour.p.group_id"
          ],
          "rows_examined_per_scan": 3,
          "rows_produced_per_join": 114,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "70.40",
            "eval_cost": "22.88",
            "prefix_cost": "146.07",
            "data_read_per_join": "11K"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      }
    ]
  }
}