Picard was born in 2305 if this is set in 2398, he'll be 93.
Picard has usually been portrayed as about a decade older than Patrick Stewart, implying greater longevity in the future (although in this he'd be about 15 years older than Stewart). In DS9, Dax once predicted that O'Brien would live to be 140, implying that that's a typical "long, full life" for a 24th-century human.