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 (
    59, 58, 60, 42, 39, 40, 37, 43, 56, 57, 30, 
    53, 52, 33, 32, 55, 29, 50, 51, 49, 48, 
    54, 65, 64, 63, 62, 66
  )

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "97.19"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "f",
          "access_type": "ALL",
          "possible_keys": [
            "idx_group_id"
          ],
          "rows_examined_per_scan": 13,
          "rows_produced_per_join": 13,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "2.11",
            "eval_cost": "2.60",
            "prefix_cost": "4.71",
            "data_read_per_join": "1K"
          },
          "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": [
            "atulecarter_atul_demo1.f.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 13,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "13.00",
            "eval_cost": "2.60",
            "prefix_cost": "20.31",
            "data_read_per_join": "5K"
          },
          "used_columns": [
            "id",
            "code"
          ]
        }
      },
      {
        "table": {
          "table_name": "p",
          "access_type": "ALL",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "rows_examined_per_scan": 49,
          "rows_produced_per_join": 35,
          "filtered": "5.51",
          "using_join_buffer": "Block Nested Loop",
          "cost_info": {
            "read_cost": "6.68",
            "eval_cost": "7.02",
            "prefix_cost": "97.19",
            "data_read_per_join": "561"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ],
          "attached_condition": "((`atulecarter_atul_demo1`.`p`.`group_id` = `atulecarter_atul_demo1`.`f`.`group_id`) and (`atulecarter_atul_demo1`.`p`.`product_id` in (59,58,60,42,39,40,37,43,56,57,30,53,52,33,32,55,29,50,51,49,48,54,65,64,63,62,66)))"
        }
      }
    ]
  }
}