SELECT 
  product_id, 
  group_id 
FROM 
  cscart_product_variation_group_products 
WHERE 
  group_id IN (
    203, 213, 204, 201, 227, 239, 415, 202, 
    221, 228, 217, 234, 207, 235, 215, 257, 
    241, 803, 205, 230
  )

Query time 0.00072

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "45.96"
    },
    "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": 91,
      "rows_produced_per_join": 91,
      "filtered": "100.00",
      "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_variation_group_products`.`group_id` in (203,213,204,201,227,239,415,202,221,228,217,234,207,235,215,257,241,803,205,230))",
      "cost_info": {
        "read_cost": "36.86",
        "eval_cost": "9.10",
        "prefix_cost": "45.96",
        "data_read_per_join": "1K"
      },
      "used_columns": [
        "product_id",
        "group_id"
      ]
    }
  }
}

Result

product_id group_id
2467 201
2468 201
2469 201
2470 201
2471 201
2472 201
2473 202
2475 202
2476 202
2477 202
2478 203
2483 203
2482 203
2484 203
2485 203
2486 203
2487 203
2488 203
2489 203
2490 204
2491 204
2492 204
2493 204
2494 204
2495 204
2496 204
2497 204
2499 205
2500 205
2503 207
2504 207
2505 207
2524 213
2525 213
2526 213
2527 213
2528 213
2529 213
2530 213
2531 213
2538 215
2540 215
2541 215
2550 217
2549 217
2548 217
2544 217
2551 217
2552 217
2534 221
2564 221
2565 221
2576 227
2577 227
2578 227
2579 228
2580 228
2581 230
2585 230
2586 230
2596 234
2597 234
2598 234
2599 234
2600 234
2601 234
2602 235
2604 235
2605 235
2606 235
2607 235
2608 235
2615 239
2620 239
2621 239
2623 241
2624 241
2625 241
2626 241
2685 257
2686 257
2687 257
2502 415
3639 415
8417 803
8418 803
8419 803
8420 803
8398 803
8415 803
8416 803
8421 803