SELECT 
  * 
FROM 
  cscart_product_feature_variants 
WHERE 
  variant_id IN (
    523, 1, 441, 1715, 276, 1714, 122, 440, 
    127, 439, 362, 438, 149, 246, 120, 279, 
    1716, 146, 59, 50, 58, 147, 280
  )

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "16.11"
    },
    "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": 23,
      "rows_produced_per_join": 23,
      "filtered": "100.00",
      "index_condition": "(`test_uchur_k`.`cscart_product_feature_variants`.`variant_id` in (523,1,441,1715,276,1714,122,440,127,439,362,438,149,246,120,279,1716,146,59,50,58,147,280))",
      "cost_info": {
        "read_cost": "13.81",
        "eval_cost": "2.30",
        "prefix_cost": "16.11",
        "data_read_per_join": "35K"
      },
      "used_columns": [
        "variant_id",
        "feature_id",
        "url",
        "color",
        "position",
        "abt__ut2_color_style",
        "abt__ut2_multicolor"
      ]
    }
  }
}