Experience tells us that most access card technology cannot stay hack-proof for more than three years.
However, that does not mean your three year old card would automatically become worthless. Even if a certain card technology is hacked in theory, but in practice, it may not be feasible to carry out the hacking. There are physical constraints such as distance from your card and hacking device portability.
One thing for sure is: your card _is_ your key. Keep your card close to you concealed and never re-use a lost card.