SELECT 
  product_id, 
  group_id 
FROM 
  cscart_product_variation_group_products 
WHERE 
  group_id IN (
    345, 418, 252, 681, 155, 466, 666, 353, 
    381, 212, 266, 664, 383, 648, 432, 373, 
    382, 673, 689
  )

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "36.26"
    },
    "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": 70,
      "rows_produced_per_join": 70,
      "filtered": "100.00",
      "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_variation_group_products`.`group_id` in (345,418,252,681,155,466,666,353,381,212,266,664,383,648,432,373,382,673,689))",
      "cost_info": {
        "read_cost": "29.26",
        "eval_cost": "7.00",
        "prefix_cost": "36.26",
        "data_read_per_join": "1K"
      },
      "used_columns": [
        "product_id",
        "group_id"
      ]
    }
  }
}

Result

product_id group_id
2227 155
2226 155
2522 212
2655 252
2719 266
2728 266
3112 345
3113 345
3042 353
3153 353
3290 373
3289 373
3377 381
3378 381
3382 382
3383 382
3385 383
3386 383
3664 418
3665 418
3832 432
3831 432
4110 466
4111 466
3811 466
5948 648
6128 648
6127 648
6126 648
6129 648
6130 648
6131 648
6132 648
6133 648
6134 648
6135 648
6041 664
6042 664
6043 664
6044 664
6045 664
6046 664
6047 664
6054 666
6055 666
6056 666
6057 666
6058 666
6059 666
5956 673
6087 673
6088 673
6089 673
6090 673
6091 673
6092 673
6093 673
5683 681
6152 681
6153 681
6154 681
6155 681
6196 689
6195 689
6194 689
6197 689
6198 689
6199 689
6200 689
6201 689
6202 689