SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31eb84d40229a4429ea3d5e2dade1e728462715a628c3616a1fa7ea599354c06' 
  AND token = 'kCD69DNtcrhGzzbpJ1KzclUmRvtwa1Py5oof+Fjk5A8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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