SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd27f6dcc9d40e0092f88d5219da55e1029b904da5012beab257a150aaf66fe0' 
  AND token = 'tDuL2QtWMgDluLLNJ1ODlE+J3vpuvD5JmctJ5UTYNQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables