SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96a27721c22fd8638be7ef0dbe856f4a8ba1062580f213db3bf8b6e008b353c1' 
  AND token = 'FJ/e+lsKSGbx17k14sAsujeQm3RkLSOFn89NrHgCvW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}