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 (
    70183, 70182, 70181, 70180, 70179, 70178, 
    70177, 70176, 74805, 74806, 81269, 
    81270, 84725, 84724, 82134, 82133, 
    82135, 82657, 82658, 82660, 82661, 
    86300, 87462, 87461, 86301, 87464, 
    87463, 86303, 86302, 86590, 86591, 
    86606, 86607, 86608, 87185, 87189, 
    87188, 87187, 87186, 87190, 87191, 
    87192, 87232, 87233
  )

Query time 0.01469

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": 44,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (70183,70182,70181,70180,70179,70178,70177,70176,74805,74806,81269,81270,84725,84724,82134,82133,82135,82657,82658,82660,82661,86300,87462,87461,86301,87464,87463,86303,86302,86590,86591,86606,86607,86608,87185,87189,87188,87187,87186,87190,87191,87192,87232,87233)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}