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"
      ]
    }
  }
}

Result

product_id group_id
908 45
134 45
1142 65
853 65
1146 66
1145 66
1144 66
1143 66
856 66
1540 114
1541 114
1542 115
1543 115
1544 116
1545 116
2258 158
2257 158
2256 158
2255 158
2260 159
2259 159
2251 159
2262 160
2261 160
2252 160
2265 161
2264 161
2263 161
2253 161
2267 162
2266 162
2254 162
2559 219
2560 219
3663 219
3833 220
2562 220
2563 220
2729 268
2730 268
2731 268
2732 268
2746 272
2747 272
2749 272
2750 272
2751 272
2752 273
2753 273
2754 273
2755 273
2756 273
2757 273
2768 275
2767 275
2773 276
2775 276
2786 277
2787 277
2788 278
2789 278
2790 278
2791 278
2792 279
2793 279
2794 279
2795 280
2796 280
2800 281
2801 281
2822 284
2823 284
2824 284
2825 284
2826 284
2860 294
2861 294
2869 297
2870 297
2871 297
2877 299
2878 299
2879 299
2880 300
2881 300
2927 307
2928 307
2929 307
2930 307
2934 308
2935 308
2936 308
2937 308
3011 315
3012 315
3013 315
3014 316
3015 316
3021 318
3022 318
3023 319
3024 319
3026 320
3030 320
3029 320
3060 331
3061 331
3062 331
3090 340
3091 340
3092 340
3093 340
3094 340
3099 342
3100 342
3140 350
3141 350
3160 355
3161 355
2760 356
3164 356
3165 356
3366 379
3367 379
3404 386
3405 386
3548 402
3549 402
3373 470
4124 470
4125 470
5129 574
5126 574
5135 576
5133 576
5151 580
5153 580
7871 783
7872 783
7873 784
7875 784
7876 784
7874 785
7877 785
8703 837
8704 837
8705 837
8706 837
10454 999
10455 999