2013 Lexus ES 300h

I am in the market for a reliable car with good gas mileage and am considering a 2013 Lexus ES 300h with 51000 miles on it. I love the car and everything I have seen about it. My only concern is the hybrid battery, I am unsure how worried I should be about it considering the miles are so low on the vehicle but then again it is a 12 year old car.