SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ef030d8a6de8647002f0f2631a4a1d9286dc48c9af054578d83edeb0e39c3e8' 
  AND token = 'UQXh+pBtMmWMq62iZ0LmMKlxsr5FdXCXtGp3PlqFuwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}