Personally, at first glance I’d go with the RAV4 Hybrid. Even though it has higher mileage, it is newer. And from anecdotal evidence, it seems that hybrid batteries that get constant but not excessive usage (rather than sitting) last longer. 

If you want a little more luxury, the NX 300h is a good choice. There is just more electric stuff to manage. Like electric latches on doors. (IIRC). 

The Prius isn’t a slouch either.  But if you need more space, the other two options would be better. If you don’t need the space, then maybe the Prius. 

In general, keep up with the maintenance schedule in the booklet. Perhaps halve the intervals for oil changes. For example instead of 10K miles, do it every 5K miles. 

Also, consider taking a drive in the freeway at least once a month, cars need exercise too!

I know some folks here and Scotty aren’t too fond of used hybrids. I think they can be decent finds depending on the circumstances. 

At 15K kilometers a year, you will most likely be set for the next 10 years, assuming you keep up with the maintenance.