SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75d33e7ef540021d44e5600933546a209532da1c0f6b62f570de79d4d95e2ad5' 
  AND token = 'VSE3M5WXTfmK8COZlRH0p/Czs92HUbx/eMQHmkDzLzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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