SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '339798cd57f27f99f769c3d1c2dda57e562b38dae09d9e937440806f1af44983' 
  AND token = '1V9s6GEc9S+Rez04qqPmzCQOmt000Wl3Jypkpfp/0zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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