If the solenoid on the shifter does click but it doesn't release the interlock, it needs adjustment or replacement. However, this interlock has two functions: 1) to prevent putting the car into gear without the brakes applied, and 2) to prevent removing the key without having it in park.

On my GS the solenoid doesn't like cold and requires some coaxing (i.e., punching the lever forward until it triggers the Park switch) when the ambient temperature is below 63°F to get the key lock to release.

Since you are apparently able to get the key out with no problem, the solenoid is at least functioning and might just need adjustment. Be forewarned, mine had the same problem as yours before I adjusted it and now it has the "I'm not in park, you may not take the key out" problem. At some point I'll replace the solenoid (considering that that little thing is about $150, I'll keep pounding the shifter for a while).