SELECT 
  * 
FROM 
  cscart_product_feature_variants 
WHERE 
  variant_id IN (
    1, 3, 366, 491, 125, 492, 494, 496, 497, 
    164, 122, 240, 121, 127, 149, 120, 123, 
    152, 234, 146, 228, 50, 57, 147, 39, 32, 
    6, 237, 238, 98, 170, 489, 165
  )

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "23.11"
    },
    "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": 33,
      "rows_produced_per_join": 33,
      "filtered": "100.00",
      "index_condition": "(`test_uchur_k`.`cscart_product_feature_variants`.`variant_id` in (1,3,366,491,125,492,494,496,497,164,122,240,121,127,149,120,123,152,234,146,228,50,57,147,39,32,6,237,238,98,170,489,165))",
      "cost_info": {
        "read_cost": "19.81",
        "eval_cost": "3.30",
        "prefix_cost": "23.11",
        "data_read_per_join": "51K"
      },
      "used_columns": [
        "variant_id",
        "feature_id",
        "url",
        "color",
        "position",
        "abt__ut2_color_style",
        "abt__ut2_multicolor"
      ]
    }
  }
}