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 (
    5601, 5602, 5603, 5604, 5605, 5606, 5607, 
    5608, 5609, 5610, 5611, 5612, 1423, 
    1424, 1425, 1426, 1427, 5136, 5137, 
    5138, 5139, 5140, 5141, 6711, 1455, 
    5164, 1445, 5154, 1456, 5165, 1446, 
    5155, 1458, 5167, 1448, 5157, 1459, 
    5168, 5158, 1820, 1821, 1822, 1823, 
    1824, 1825, 1826, 1827, 1828
  )

Query time 0.00060

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "100.81"
    },
    "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": 48,
          "rows_produced_per_join": 48,
          "filtered": "100.00",
          "index_condition": "(`gaseus`.`p`.`product_id` in (5601,5602,5603,5604,5605,5606,5607,5608,5609,5610,5611,5612,1423,1424,1425,1426,1427,5136,5137,5138,5139,5140,5141,6711,1455,5164,1445,5154,1456,5165,1446,5155,1458,5167,1448,5157,1459,5168,5158,1820,1821,1822,1823,1824,1825,1826,1827,1828))",
          "cost_info": {
            "read_cost": "28.81",
            "eval_cost": "4.80",
            "prefix_cost": "33.61",
            "data_read_per_join": "768"
          },
          "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": [
            "gaseus.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 48,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "12.00",
            "eval_cost": "4.80",
            "prefix_cost": "50.41",
            "data_read_per_join": "18K"
          },
          "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": [
            "gaseus.p.group_id"
          ],
          "rows_examined_per_scan": 3,
          "rows_produced_per_join": 144,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "36.00",
            "eval_cost": "14.40",
            "prefix_cost": "100.81",
            "data_read_per_join": "14K"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      }
    ]
  }
}