If after you use the key it appears in your keyring list when you do /key - then yes it would become part of the keyring. No matter what anyone tells you here, it is good practice when it comes to keys and flagging items to do /key to make sure.
I am aware that this key is the result of a quest. However, the name and grahpic looks familiar. If you take a wizard port to Plane of Sky, and get that key bearer guy to pop on the first island, you can buy stuff from him. For 1cp you can buy something called Key to Veeshan .... I think or is it Veeshan's Key? something to look into... but I'm pretty sure that they keys sound the exact same, or very similar...
It is the key to Veeshan's Peak in Skyfire Mountains. A zone with nothing but named dragons and all the common mobs you see in Skyfire but 100% tougher. You get the key from a very very long and time consuming quest. But it is very worth it in the end.