SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '033a3221c893dea73f330b656496140e19756e862321f2581f86bc4a564c33f8' 
  AND token = 'LgbmM+tKlCMJytb2GYB4aEYRk0qiKCctZHjhO0IyKtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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