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 (
    74235, 74234, 74233, 74236, 74243, 74242, 
    74241, 74244, 74247, 74246, 74245, 
    74248, 74251, 74250, 74249, 74252, 
    74255, 74254, 74253, 74256, 74259, 
    74258, 74257, 74260
  )

Query time 0.00251

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": 24,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (74235,74234,74233,74236,74243,74242,74241,74244,74247,74246,74245,74248,74251,74250,74249,74252,74255,74254,74253,74256,74259,74258,74257,74260)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}