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 (
    68796, 68795, 70183, 70182, 70181, 70180, 
    70179, 70178, 70177, 70176, 70239, 
    70238, 70237, 70236, 70235, 70234, 
    71596, 71595, 71594, 71593, 71592, 
    71591, 71597, 74591, 74593, 74594, 
    74596, 74650, 74649, 74651, 76637, 
    76635, 76636, 80580, 80581, 80584, 
    80585, 80586, 81495, 81496, 81872, 
    81879, 81880, 81873, 81877, 81878, 
    81874, 81875, 81876, 87464, 87463, 
    86303, 86302, 87452, 87451
  )

Query time 0.01116

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": 55,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (68796,68795,70183,70182,70181,70180,70179,70178,70177,70176,70239,70238,70237,70236,70235,70234,71596,71595,71594,71593,71592,71591,71597,74591,74593,74594,74596,74650,74649,74651,76637,76635,76636,80580,80581,80584,80585,80586,81495,81496,81872,81879,81880,81873,81877,81878,81874,81875,81876,87464,87463,86303,86302,87452,87451)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}