Royal pardon or more formally "Royal prerogative of mercy" exists in the U.K. Formally it is power of the crown, however in practice it is delegated to Lord Chancellor in England. Scotland has a different structure for this AFAIK.
Craig Murray is a former ambassador and supports Scottish independence so it would be lot more complicated even if the government wanted to do something about it. Also it is only 8 month sentence, so it won't make any practical difference if some future government post-facto does pardon him.
Side note: U.S. tooks its legal system largely from England and made modifications as they thought fit, presidential pardons were specifically designed to mirror the royal pardon without the monarchy part of it.
Craig Murray is a former ambassador and supports Scottish independence so it would be lot more complicated even if the government wanted to do something about it. Also it is only 8 month sentence, so it won't make any practical difference if some future government post-facto does pardon him.
Side note: U.S. tooks its legal system largely from England and made modifications as they thought fit, presidential pardons were specifically designed to mirror the royal pardon without the monarchy part of it.