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 (
    51514, 51538, 51539, 51468, 51476, 51491, 
    51513, 51474, 51503, 51520, 51522, 
    51541, 51462, 51502, 51499, 51465, 
    51509, 51515, 51466, 51485, 51518, 
    51550, 51519, 51524, 51528, 51508, 
    51527, 51543, 51482, 51504, 51542, 
    51512
  )

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "44.81"
    },
    "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": 32,
          "rows_produced_per_join": 32,
          "filtered": "100.00",
          "index_condition": "(`test_uchur_k`.`p`.`product_id` in (51514,51538,51539,51468,51476,51491,51513,51474,51503,51520,51522,51541,51462,51502,51499,51465,51509,51515,51466,51485,51518,51550,51519,51524,51528,51508,51527,51543,51482,51504,51542,51512))",
          "cost_info": {
            "read_cost": "19.21",
            "eval_cost": "3.20",
            "prefix_cost": "22.41",
            "data_read_per_join": "512"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ]
        }
      },
      {
        "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": [
            "test_uchur_k.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 32,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "8.00",
            "eval_cost": "3.20",
            "prefix_cost": "33.61",
            "data_read_per_join": "3K"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "test_uchur_k.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 32,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "8.00",
            "eval_cost": "3.20",
            "prefix_cost": "44.81",
            "data_read_per_join": "12K"
          },
          "used_columns": [
            "id",
            "code"
          ]
        }
      }
    ]
  }
}