SELECT 
  product_id, 
  group_id 
FROM 
  cscart_product_variation_group_products 
WHERE 
  group_id IN (
    236, 349, 231, 274, 259, 341, 267, 271, 
    405, 233, 343, 238, 285, 237, 240, 298, 
    262, 408, 546, 388, 270, 656, 291, 581, 
    437, 430, 573, 658, 296, 657, 660, 582, 
    572, 659, 699, 653, 654, 951
  )

Query time 0.00089

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "61.71"
    },
    "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": 116,
      "rows_produced_per_join": 116,
      "filtered": "100.00",
      "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_variation_group_products`.`group_id` in (236,349,231,274,259,341,267,271,405,233,343,238,285,237,240,298,262,408,546,388,270,656,291,581,437,430,573,658,296,657,660,582,572,659,699,653,654,951))",
      "cost_info": {
        "read_cost": "50.11",
        "eval_cost": "11.60",
        "prefix_cost": "61.71",
        "data_read_per_join": "1K"
      },
      "used_columns": [
        "product_id",
        "group_id"
      ]
    }
  }
}

Result

product_id group_id
2587 231
2588 231
2589 231
2590 231
2593 233
2594 233
2595 233
2603 236
2609 236
2610 236
2611 236
2613 237
2614 237
2617 238
2618 238
2619 240
2622 240
2696 259
2697 259
2695 259
2694 259
2704 262
2705 262
2706 262
2723 267
2724 267
2725 267
2726 267
2739 270
2740 270
2741 270
2742 271
2743 271
2744 271
2745 271
2761 274
2762 274
2763 274
2764 274
2828 285
2830 285
2831 285
2841 291
2849 291
2850 291
2865 296
2866 296
2867 296
2872 298
2873 298
2874 298
2875 298
3096 341
3097 341
3098 341
3104 343
3105 343
3106 343
3136 349
3137 349
3138 349
3423 388
3422 388
3610 405
3556 405
3557 405
3593 408
3594 408
3812 430
3813 430
3876 437
3877 437
4888 546
4891 546
4892 546
5122 572
5121 572
5124 573
5125 573
5155 581
5156 581
5157 582
5158 582
5979 653
5980 653
5981 654
5982 654
5984 654
6221 654
5999 656
5997 656
5998 656
6000 656
6001 656
6002 656
6003 657
6004 657
6005 657
6007 658
6008 658
6009 658
6010 658
6011 658
6012 658
6013 659
6014 659
6015 659
6019 660
6020 660
6021 660
6022 660
6023 660
6271 699
6272 699
10022 951
10028 951