Agatha Christie's "The Mousetrap" has set some kind of record by running more than 25 consecutive years in London. "Black Coffee," now in its "American premiere" at Olney Theater, opened and closed in London in 1930, thereby setting Christie's record for shortgevity.

It was the great mystery writer's first play, with none of the fast-paced sophisticated of her later hit plays. The basic structure - "Nobody is allowed to leave this room until we find out which one of you . . ." - is a bit bald; and while the butler may or may not have done it, he is certainly guilty of saying "You ra-a-a-ang, sir?" every time he enters the room.

Olney has chosen to play it for a kind of period comedy, making up with charm for the lack of eerie suspense. The production is not unlike that of "Dracula" at the Kennedy Center - a well-furnished drawing room, pearl necklaces, tinkling laughter and references to "motor cars." These attributes are both pleasant in themselves, in these days of stark stages with risers instead of chairs, and useful as a contrast with the distinctly uncivilized crime of murder.

"Black Coffee" is a Hercule Poirot play. The great Belgian detective was later to polish up his act, but Robert Symonds, in tailcoat, mustache, center part and with the lips pursed while simultaneously raising the eyebrows, gives him his full comic potential. With lines such as "I tell you my friend, we have been drama! No simple human crime but drama - poignant drama!" what else can he do? He is also good at pronouncing the word "he" as if it were spelled "'eeeee.'"

Similarly, the others in the cast do your standard set of British-detective story suspects - upper-class loose blonde by Gwyn Gillis, passionate and troubled foreign lady by Mary Anne Dempsey, dopey assistant to detective who is useful to audience because it has to be spelled out to him what is going on, by Michael Rothhaar - with great good humor. The best is Joan White as the fussy, garrulous old lady obligatory to this sort of entertainment.