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 (
    82231, 82240, 82241, 82242, 82243, 82244, 
    82245, 82246, 82247, 82248, 82249, 
    82250, 82232, 82233, 82234, 82235, 
    82236, 82237, 82238, 82239, 82251, 
    82252, 82253, 82260, 82261, 82262, 
    82271, 82272, 82273, 82274, 82275, 
    82276, 82277, 82278, 82279, 82280, 
    82281, 82263, 82264, 82265, 82266, 
    82267, 82268, 82269, 82270
  )

Query time 0.00322

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": 45,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (82231,82240,82241,82242,82243,82244,82245,82246,82247,82248,82249,82250,82232,82233,82234,82235,82236,82237,82238,82239,82251,82252,82253,82260,82261,82262,82271,82272,82273,82274,82275,82276,82277,82278,82279,82280,82281,82263,82264,82265,82266,82267,82268,82269,82270)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}