The Key is in the Aquarium which is in Wladimir Kalenkow's House and at the beginning you can't get it. At first you have to solve the Mission Repair Lisas bicycle, then repair the Camera and you become the Magnet to pull up the Key at the glass from the aquarium.
The Mission listed Edit
- Repair Lisas bicycle
- Repair the camera
- Drive to Wladimirs House (via motorbike)
- Use the magnet on the Aquarium