That looks like an ale yeast- that's pretty cold for an ale yeast, so I would expect that it wouldn't ferment very well at all.
What was the recipe? Did you take any SG readings since the beginning? I'd take the SG and see where it was at, and try to get it above 65 degrees.
There's some confusion here, because a true pilsner beer is a lager, which is fermented around 50 degrees or so. But many kits aren't instructing you to use lager yeast and to do that, so it's actually an ale kit. If you're making an ale kit, then it should be fermented at the yeast's optimum fermenting temperature. From Munton's website, I found this:
Muntons Standard Yeast
It has very hardy characteristics and will tolerate a wide variety of temperature variations during fermentation.
For recipes demanding the use of sugar our Standard Yeast is ideal. If all malt brewing is undertaken we would recommend that you use our Premium Gold Yeast as our Standard Yeast will struggle to ferment some of the more complex sugars which are more prevalent in all malt recipes.
The major benefit for you of using Muntons Standard Yeast is its relatively low cost.
All of our yeasts are supplied in six gramme sachets sufficient to brew five U.K.gallons, six U.S. gallons or twenty three litres of beer.
So, I'd check the SG and see if it was finishing up. If not, I'd put it somewhere in the mid 60s to get it going.