SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a049234c50446abbbebadbdf925b857df9b623d43aeec88a7b2ea1596b14ab0' 
  AND token = 'WjZ9Rf5ud2bSBVvza/VaXrrjG4XOeYp/x956mAcrxcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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