SELECT 
  product_id, 
  group_id 
FROM 
  cscart_product_variation_group_products 
WHERE 
  group_id IN (
    45, 340, 273, 66, 219, 284, 161, 272, 158, 
    307, 268, 350, 115, 320, 65, 114, 116, 
    159, 160, 162, 297, 299, 278, 280, 308, 
    279, 318, 470, 315, 356, 331, 300, 316, 
    386, 379, 355, 319, 342, 281, 294, 276, 
    275, 220, 402, 580, 277, 574, 576, 837, 
    784, 783, 785, 999
  )

Query time 0.00114

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "80.76"
    },
    "table": {
      "table_name": "cscart_product_variation_group_products",
      "access_type": "range",
      "possible_keys": [
        "idx_group_id"
      ],
      "key": "idx_group_id",
      "used_key_parts": [
        "group_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 150,
      "rows_produced_per_join": 150,
      "filtered": "100.00",
      "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_variation_group_products`.`group_id` in (45,340,273,66,219,284,161,272,158,307,268,350,115,320,65,114,116,159,160,162,297,299,278,280,308,279,318,470,315,356,331,300,316,386,379,355,319,342,281,294,276,275,220,402,580,277,574,576,837,784,783,785,999))",
      "cost_info": {
        "read_cost": "65.76",
        "eval_cost": "15.00",
        "prefix_cost": "80.76",
        "data_read_per_join": "2K"
      },
      "used_columns": [
        "product_id",
        "group_id"
      ]
    }
  }
}