SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9edfb091db16428d0a359ff41adb9014dd4830680430a29e915dea9748acf47' 
  AND token = 'xcWM55dmeE+Ai9s8YREDzyL4CKZD9WcJ0YZNkPvOFjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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