This is a very common objection experienced candidates are face during their job search, if they make it to the interview round.
So the genuine concern for the hiring manager is that you might look like a liability since they don’t want to hire an employee who will leave them in a few months due to boredom. From the hiring managers perspective, they prefer long term commitment rather than a short term engagement.
Step 1: Understand the objection
As a rule of thumb, it is how to respond and not react, that will determine the outcome of the interview. However to give a professional thought-out response you must first understand the objection. So if the hiring manager brings up the question of qualification, first clarify how they see you as overqualified for this position?
Step 2: Build your response
Once you have a better understanding of their objection, take a deep breath and think of your answer before jumping in with a reply.
This is your opportunity to sell yourself. so start by describing exactly what appeals to you about this role. Needless to say, you have already done your in-depth research about the company, the role, culture, people, … (at least) before coming to the interview if not earlier when applying to the job.
This is also an opportunity to talk more about the company and culture that attracted you to apply in the first place. Perhaps you like the direction the company I heading into? All of these insights will come through research.
Last but certainly not the least, express your long-term commitment.