Journals with quick reviewing
Glencora Borradaile has an interactive graph with turnover time (among other information) for several journals from several sources.

However, not included is the first journal I think of with a fast turnaround time: Information Processing Letters (IPL).  I couldn't find any statistics, but rapid dissemination is their first goal.  When refereeing for a similar Elsevier journal with the same goal of rapid dissemination but with a slightly different scope, they requested my report within about 5 weeks.