If your talking about Counterfeit Island then you get the key and go back to the museum on Counterfeit Island
The key card is for later. Return to the museum, where you have a package waiting for you.
You now have a key that fits a lock on Counterfeit Island, and you haven't found a key to the lock on the Inspector's house, so...
I forget but I think the lady in the museum gives the key to you...
You do nothing for now, you will need it later on in the game. But after you get the key card walk in the museum and there will be a package for you.
Go back to the museum. You have a package waiting.
You take it back to counterfeit Island and use it on the door of the house.
Once you get the key from the curator, go back to Counterfeit island and use it at the Inspector's house.
Museum of Counterfeit Goods was created in 1989.
first you get a package to meet the creator on Early poptropica at the museum and she gives you the key
After you chase the thief on the scooters, you can go to Early Poptropica, where the Curator will meet you in the Pop Art museum to give you the key. (You get a package at the museum with this message.)
Pick up the key card and go back to the museum. You have a package there.