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 (
    242, 243, 6, 66, 166, 214, 219, 221, 223, 
    240, 241, 244, 245, 246, 248, 247, 278, 
    280, 282, 286, 287, 289, 315, 331, 335, 
    339, 341, 345, 346, 349, 350, 352
  )

Query time 0.00098

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 (242,243,6,66,166,214,219,221,223,240,241,244,245,246,248,247,278,280,282,286,287,289,315,331,335,339,341,345,346,349,350,352))"
        }
      },
      {
        "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"
          ]
        }
      }
    ]
  }
}