SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48312c6820a041b725e2e46acc12a3a3c4b73919393927f37f87a9becdc5b3be' 
  AND token = 'UizvYgocPVteTJnTaiovJzB3+pU5eNc6gERttExdclw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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