SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '788a4e2326f16a8927dacfd88e3ddb31bbed7391abaf56d88743fa2674fdc3a2' 
  AND token = 'vwaVqQf3zRxs/NS5cfMVr/vyvBUIWr+Fe13fVH5l9OA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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