SELECT 
  * 
FROM 
  cscart_product_feature_variants 
WHERE 
  variant_id IN (
    1, 3, 1351, 289, 125, 126, 414, 1348, 419, 
    1347, 424, 428, 122, 121, 127, 1349, 
    149, 120, 124, 123, 234, 146, 59, 50, 
    57, 147, 24, 25, 26, 426, 423, 421, 422, 
    111, 1296, 237, 238, 165, 320
  )

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "27.31"
    },
    "table": {
      "table_name": "cscart_product_feature_variants",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "variant_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 39,
      "rows_produced_per_join": 39,
      "filtered": "100.00",
      "index_condition": "(`test_uchur_k`.`cscart_product_feature_variants`.`variant_id` in (1,3,1351,289,125,126,414,1348,419,1347,424,428,122,121,127,1349,149,120,124,123,234,146,59,50,57,147,24,25,26,426,423,421,422,111,1296,237,238,165,320))",
      "cost_info": {
        "read_cost": "23.41",
        "eval_cost": "3.90",
        "prefix_cost": "27.31",
        "data_read_per_join": "60K"
      },
      "used_columns": [
        "variant_id",
        "feature_id",
        "url",
        "color",
        "position",
        "abt__ut2_color_style",
        "abt__ut2_multicolor"
      ]
    }
  }
}