About 45 minutes driving.
According to Google Maps, it's 69.9 miles (112 km) from Anchorage to Willow. It should take about 1 hour and 17 minutes to drive, on average.
828.62 kilometres (514.88 miles)
35.24 kilometres (21.89 miles)
1,805.72 kilometres (1,122.03 miles)
It is 11.60 miles according to MapQuest.