Btw, the airport is right next to Fuenterrabia or Hondarribia, a very nice little town with a fisherman's quarter, city walls and a middle age kind of town square. It is definitelly worth a day trip, only 20~30" from San Sebastian. Spain is very safe, specially the Basque country area.
Being at the airport 45" is more than enough. I use it 4~6 every year and it's a great little airport. In and out in 5" if no luggage.