SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8af7b4674962c4ef65bca12e177a27627285b5d69f1cd476c16eb7881bad8ceb' 
  AND token = 'Gu8lnPXiKixlSAUyCoI9+KZQykUjH8S3J23d9WHmXRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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