Treasure keys were a type of loot Sly Cooper had to obtain in Sly Cooper and the Thievius Raccoonus. Each member of the Fiendish Five, excluding Clockwerk, had hidden most of them in trophy cases in the far corners of their environments.
These key are light blue in color, with yellow handles. Plus, they always feature a golden glow on them, usually seen when collecting a key and using them to unlock certain things.
Sly would begin a mission that ends near a way to the hub, in which he had to do a little moving to get there. The first key would be near the end of the zone's starting area. Keys were earned for reaching the end of an area or could be earned as a prize. Three to four keys would grant access to the other half of the hub, while seven keys would grant access to the boss' main quarters.
There were two different types of missions in the game in which Murray had to obtain a key instead. One involved Sly using a blaster to defend Murray as he made a run for the key. Another one involved Murray winning a three-lap race in the team van to obtain the key as the prize. There were four missions in total for Murray.