An equivalent question is, are sociopaths happy?
The best answer I can think of is: are great white sharks happy? Just as it's hard to imagine a great white shark getting depressed, it's also hard to imagine them feeling peacefully contented. They must get a feeling of satisfaction from grabbing a seal in their jaws, shaking it, and ripping the flesh off it. But it's a temporary feeling, and great white sharks have to keep moving, or they die.
These sharks are always ravenous, never quite sated, and remain on a sort of psychic autopilot. They are not inward-looking, introspective creatures. And they never stop to worry about whether what they're doing is "right."
In fact, even in the womb, they'll devour their own siblings.
And they spend the rest of their lives looking of their next victim.
Sociopaths are much the same. They always want more, and will do anything to get it.
Sociopaths feel physical pleasure every bit as much as the next person. In fact, because of their low level of inhibitions, they find physical pleasure hard to resist.
And sociopaths enjoy the feeling of schadenfreude even more than the rest of us; they are connoisseurs of it.
Although sociopaths can counterfeit love, affection, gratitude, and loyalty so well that to the naive they appear to be walking repositories of those emotions, they never actually feel them. So they never feel the warmth of those emotions can bring.
Sociopaths also get a certain glee from fooling people -- sport lying -- but it's a very temporary satisfaction, then it's on to the next one.
Similarly, for "affect-hungry" sociopaths, like the one described in the previous post, who have a bottomless need for others' affection and sympathy and admiration -- and who will lie in order to receive such -- no amount of attention is ever enough. So they must tell more people that they have cancer, or that they were Navy SEALs, or whatever other lies it takes to get their undivided attention.
There's no rest for the scary.