SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7c41f4bba6bf51f88b7451530f608da449cf1f20d25b0c4a7050a4dff77ffbb' 
  AND token = 'l7jq+A9bXoPzGgVOCfcUhQtudZo9GDavkC86oC7m2BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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