Just say things like you want to continue to contribute in any way possible. You want to be working at the same intensity levels but producing more because you'll have increased in knowledge, and efficiency, i.e. you'll be leveraging your experience to work smarter.
I agree with others -- just keep your mouth shut and play the game. Find a way to say what your manager wants to hear without compromising your integrity. The more you adhere to what s/he expects you to say, the faster the meeting will be over because fewer questions will be asked.
You never know about your 5-year retirement plan, anyway. Things change. It might turn into a 4-year plan or a 10 year. You might have to work longer than you think for whatever reason. So you're not exactly lying.