I recall a pretty darn nice joint from a golf trip vaca perhaps 5 years ago. I believe it is called Players. It is in a strip mall, on Route 17, on the east side. North side of Myrtle... Fairly upscale as joints go, full bar, and upstairs.
Try Smokehouse Billiards just off the bridge on Waccamaw which runs parallel with W Broadway. Not sure when the open but call first 843-903-4288. If you like bar boxes, Brick House Lounge in Surfside Beach (old Hwy 17) has I think 6 Valley's. I was there in May and not too busy. Out in Conway, there is Breakroom Billiards but it's off the beaten path of Myrtle.