Not knowing anything about you, your body as it is, your life's circumstances, your history of physical activity, and your health over the past five years or so, I would say that rate is a tad on the low side. Maybe your Vagus nerve is very aggressive and when you're calm it wants to nub your heart's activity. Or, you're just a naturally calm person, fit, no pathology, contented with your circumstances, and you have few if any worries.

It's cheap insurance, now, when you don't feel awful or overly worried, to get an ECG to see if anything is amiss or bears watching. This is strictly my opinion and what I would seek.

If you never have any dyspnea, syncope upon standing, and moving around, when climbing steps, or even when bending over to retrieve something from the floor, I would say you're probably not doing badly. But an ECG will possibly show something that bears an eagle's eye.