FlyingStone - a similar rule of thumb was used on the corporate jet I used to fly, which had no such planning charts.
Cruise level = ground distance adjusted by a fudge factor for especially strong head/tail wind. Worked very nicely.
I have seen LIDO come up with very different answers for the same short route (~300nm) on the 738 in similar wind conditions - some solutions were FL190, others 330-350 with the aforementioned one minute cruise which in practice due to ATC issues always ended up with you stuck very high indeed.
A similar short trip cruise graph to that posted by FlightDetent for the 320 is in the NG simplified flight planning section of the performance manual (2.2.1 for those who have access) with curves for cruise time of 1, 5, 10, 15 and 20 min. The minimum trip fuel line runs from around 5 min cruise at 50nm FL100 to 14 min cruise at FL400 for 260nm.