It’s a rich, slow-spreading smile, like butter melting in a skillet over a low flame. And whenever it creeps across James Corden’s face in the splendidly silly “One Man, Two Guvnors,” which opened on Wednesday night at the Music Box Theater, you know two things for sure: You’re in for trouble, and you’re already hooked. Struggle as you will, there ain’t nothing you can do about it. That smile captures the essence of “One Man, Two Guvnors,” Richard Bean’s inspired adaptation of an 18th-century Italian farce by Carlo Goldoni, directed by Nicholas Hytner. A runaway hit in London, where it originated at the National Theater, “One Man” is, like Mr. Corden’s grin, both satanic and seraphic, dirty-minded and utterly innocent. Letting loose and neutralizing all sorts of demons, it’s ideal escapism for anxious times.