I had a strategy for this that I frequently recommend to people. Back when I was "in the game" and living in NYC, I used to take 1-2 interviews per month despite being happy in my then current role. I was up front with current and prospective employers about this.

This strategy served me well on many fronts: confidence in my skills and my options, familiarity with evolving interview trends, and networking opportunities with team leaders in a tight knit industry. It also allowed me to chase roles/positions which I wasn't immediately qualified for without feeling stress and anxiety, and was immensely helpful later on as an engineer turned startup CEO to know what product/project management interviews should feel like.