The most definitive sign an ignition system might not work properly would be a car's failure to start. When the vehicle doesn't turn over, the ignition system might be the source of the problem. Slow starts or sputtering might not be as "definitive," but don't think things won't get worse. Ignoring any signs of trouble could lead to things getting worse, possibly at the worst possible moment.
"Minor" things, such as the key not turning, may not be as severe as problems with the ignition, starter, or engine, but the inability to turn the key means you won't be able to start the car. Hopefully, the necessary fix won't be too difficult or costly.
Did you notice any flickering dashboard lights? They might flicker and then return to normal, but that doesn't necessarily mean the problem went away. Get it checked, or else run the risk of stalling in or around Anchorage, AK, or elsewhere.
MINI of Anchorage is home to a service department. Book repairs and maintenance here.