How do you find a job With Work Life Balance

I'm intending to change my job after my maternity leave. I have no support to take care of my LO (mum is not ard, can't depend on in laws and no helper). Hence it is important for me to find a job that has work life balance and can leave work on time to pick up my LO from infant care. I'm in the Finance/Acct industry though and it is often required to do OT in this field. How do I ensure that I can find a job with work life balance? Will it put interviewers off if I mentioned during interviews that I can't OT? Will this jeopardise my chances of having good jobs in the market? Any Mummies can advise? Esp those in this line of work?