SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f35d842238242d62bf88af15b7953ee80a4abd48dc32eb64d7ecbb6ee2d6fcd7' 
  AND token = 'R0APF4QZatru4p7+Uwci3CJdfIB7uDTFkcdmdw7wOhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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