SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48f21ac088f0a2540afc7c75180c7adb6473fa45e929af64c62fdf8a5ebbda25' 
  AND token = 'RlovN5OK6rpq/qUbW9WXI8GTmfAQ7IY0Mn++qFTbwUE=' 
  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