Well-kempt is redundant. The word kempt means neat, tidy, well-groomed. Its opposite is unkempt;a slovenly person. In popular usage, however, we usually prefix kempt with well - as in, he's well-kempt. On the other hand, it is entirely wrong to define a neat guy by saying he's well-kept - unless he's a gigilo or hustler, being more than adequately paid.
My boyfriend really grooms himself well, he's always perfectly kempt. Or, if you like, well-kempt.