Keegan-Michael and Elle know more than a few of the Key characteristics of successful sketch comedy. Which means they would be the first to point out that lines like that don’t pass muster. Keegan-Michael Key, half of the famed “Key & Peele” comedy duo, and his wife, Elle Key, a writer, director and producer, have translated their award-winning podcast, “The History of Sketch Comedy,” into a hilarious and informative new book.