SELECT 
  pfv.variant_id, 
  pfv.position, 
  pfvd.variant 
FROM 
  cscart_product_feature_variants AS pfv 
  INNER JOIN cscart_product_feature_variant_descriptions AS pfvd ON pfv.variant_id = pfvd.variant_id 
  AND pfvd.lang_code = 'vi' 
WHERE 
  pfv.variant_id IN (
    68994, 68993, 68992, 68991, 68990, 68989, 
    68988, 68987, 68995, 68986, 69012, 
    69011, 69010, 69009, 69008, 69007, 
    69006, 69005, 69013, 69004, 69020, 
    69019, 69018, 69017, 69016, 69015, 
    69021, 69014, 69030, 69029, 69028, 
    69027, 69026, 69025, 69024, 69023, 
    69031, 69022, 70039, 70038, 70037, 
    70036, 70040, 70035, 70051, 70050, 
    70049, 70048, 70052, 70047, 70064, 
    70063, 70062, 70061, 70060, 70065, 
    70059, 70077, 70076, 70075, 70078, 
    70074, 70085, 70086, 70084, 71589, 
    71588, 71587, 71586, 71585, 71590, 
    72337, 72336, 72338, 81325, 81332, 
    81328, 81333, 81327, 81326, 81329, 
    81330, 81331, 81927, 81928, 81929, 
    74389, 82449, 82450, 74391, 74392, 
    74393, 74394, 74395, 74396, 74397, 
    74399, 74407, 82455, 74412, 82456
  )

Query time 0.01224

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "pfv",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["variant_id"],
          "rows": 101,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (68994,68993,68992,68991,68990,68989,68988,68987,68995,68986,69012,69011,69010,69009,69008,69007,69006,69005,69013,69004,69020,69019,69018,69017,69016,69015,69021,69014,69030,69029,69028,69027,69026,69025,69024,69023,69031,69022,70039,70038,70037,70036,70040,70035,70051,70050,70049,70048,70052,70047,70064,70063,70062,70061,70060,70065,70059,70077,70076,70075,70078,70074,70085,70086,70084,71589,71588,71587,71586,71585,71590,72337,72336,72338,81325,81332,81328,81333,81327,81326,81329,81330,81331,81927,81928,81929,74389,82449,82450,74391,74392,74393,74394,74395,74396,74397,74399,74407,82455,74412,82456)"
        }
      },
      {
        "table": {
          "table_name": "pfvd",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["variant_id", "lang_code"],
          "ref": ["dev_db.pfv.variant_id", "const"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "pfvd.lang_code = 'vi'"
        }
      }
    ]
  }
}