SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27852dd893ccbd1b403847bc337d5ff173a4d312f58d2cc6538592cd1815f93b' 
  AND token = 'xSdnsNP6LryQ3H2rf/wCY4lX8Pia4oOSo9Qd8zQzE7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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