SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adc606f558080bf78ce91970192ad87caaec8e8c518e64a18caccbcd14ef1608' 
  AND token = 'VEl9awL2tSxQQoLSOVT6eW5WzGbRzqtla48/4m6/otk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

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