I dont remember if first time I found the sable and white dog statue I forget to search or if later I sold the gold key by mistake. The fact is that now I haven't it and can't get it searching in the statue.
This is a needed item to do the main quest so, any idea how can I get a gold key?

Etherealiza and teleport doesn't work to enter the golden door in castle doom, so after some time thinking I began the quest from sorpigal and after getting the ruby whistle again from the brothers the statue in the stronghold
in enchanted forest so I finally get the golden key

Problem solved