SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1508f5daf526dc4c596afcf1bb14e7c0883c828e3b7a5278ca64226757499158' 
  AND token = 'iBIDVyDDkdhJZLg3pS7Lxn3CGTj9KRS0pBnN3bLX5LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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