I hate to say it, but there is an expectation that people will retire any time after 60. I'm not sure of the size of your company, or the skill level of the job, but companies have to make an investment in training. They may have to weigh the pros and cons of offering training to someone they think may retire.
I personally wouldn't be offended if I was asked about plans at that age. They may value your experience and skills and want to know if you plan to be around for another 5 years, or they may want to so some succession planning to train more staff.
I hoped that I would never become that person who was a bit complacent, but I think to a certain degree I am. There is talk of a new software package coming to our company, which involves intensive training. I'm really hoping that it is scheduled to arrive after my loosely planned retirement (at 62). Honestly, I m not looking forward to a huge learning curve, and while I have been a lead in the past, I think I would defer to someone in the same department who is younger to take the lead in training.
If you are planning in staying in the workplace for as long as possible, let HR know you are enthusiastic and plan on offering your expertise for as long as possible. It may even lead to a promotion.