I would leave it alone... if the beer is fermenting, it isn't too cold! Lager yeast+cold ferment= clean beer/good lager. This should be an excellent beer.
45ish is my SOP ferm temp for lagers and have actually gone as low as 35 once, stepping down slowly over a week or so, and still had active ferment. The beer was amazing... it took a long time to ferment at that temp, but that was kind of the point.
"Why did you.... what was the point of... how drunk were you when you decided this was a good idea?" - DMartin