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, 69668, 69669, 70239, 70238, 
    70237, 70236, 70235, 70234, 71575, 
    71573, 71574, 71596, 71595, 71594, 
    71593, 71592, 71591, 71597, 72988, 
    72987, 72986, 72985, 72984, 72983, 
    72982, 72981, 72980, 72989, 73005, 
    73004, 73003, 73002, 73006, 74588, 
    74590, 74594, 74596, 74650, 74649, 
    74651, 77117, 77112, 77113, 77114, 
    77115, 77116, 85250, 85249, 85251, 
    85252, 85253, 85254, 86300, 87462, 
    87461, 86301, 87464, 87463, 86303, 
    86302, 87098, 87097, 87096, 87094, 
    87095, 87452, 87451
  )

Query time 0.01350

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": 69,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (68796,68795,69668,69669,70239,70238,70237,70236,70235,70234,71575,71573,71574,71596,71595,71594,71593,71592,71591,71597,72988,72987,72986,72985,72984,72983,72982,72981,72980,72989,73005,73004,73003,73002,73006,74588,74590,74594,74596,74650,74649,74651,77117,77112,77113,77114,77115,77116,85250,85249,85251,85252,85253,85254,86300,87462,87461,86301,87464,87463,86303,86302,87098,87097,87096,87094,87095,87452,87451)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}