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 (
    80194, 80193, 80192, 80191, 80190, 80212, 
    80211, 80210, 80209, 80208, 80207, 
    80206, 80205, 80216, 80215, 80214, 
    80213, 80220, 80219, 80218, 80217, 
    83157, 83158, 83159, 83160, 83177, 
    83178, 83179, 83180
  )

Query time 0.00401

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": 29,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (80194,80193,80192,80191,80190,80212,80211,80210,80209,80208,80207,80206,80205,80216,80215,80214,80213,80220,80219,80218,80217,83157,83158,83159,83160,83177,83178,83179,83180)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}