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 (
    5272, 4991, 5932, 2354, 4226, 3346, 4431, 
    5276, 4275, 4195, 3493, 3342, 1566, 
    4460, 5613, 5925, 5285, 5346, 5196, 
    1631, 3597, 5670, 3938, 3345
  )

Query time 0.00086

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "35.91"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "p",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "product_id"
          ],
          "key_length": "3",
          "rows_examined_per_scan": 26,
          "rows_produced_per_join": 26,
          "filtered": "100.00",
          "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`p`.`product_id` in (5272,4991,5932,2354,4226,3346,4431,5276,4275,4195,3493,3342,1566,4460,5613,5925,5285,5346,5196,1631,3597,5670,3938,3345))",
          "cost_info": {
            "read_cost": "15.11",
            "eval_cost": "2.60",
            "prefix_cost": "17.71",
            "data_read_per_join": "416"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "softwarepirmam_hewadelivard_cscart_4.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 26,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "6.50",
            "eval_cost": "2.60",
            "prefix_cost": "26.81",
            "data_read_per_join": "10K"
          },
          "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": [
            "softwarepirmam_hewadelivard_cscart_4.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 26,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "6.50",
            "eval_cost": "2.60",
            "prefix_cost": "35.91",
            "data_read_per_join": "2K"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      }
    ]
  }
}