"Somewhere Only We Know" reached the British top five in 2004 and then had a second life in 2013 when Lily Allen's cover, used in a Christmas advertisement, went to number one, pushing the original back into wide circulation.
Keane are a strange choice for the one-hit question given their album record: five of their releases have gone to number one in Britain, and Hopes and Fears is among the best-selling albums of its decade there. "Everybody's Changing", "Bedshaped", "Is It Any Wonder?" and "Crystal Ball" all reached the UK top twenty, and they won the Brit Award for Best British Breakthrough Act.
On streams the ratio sits near 3, under our 5.0 line for a certified one-hit wonder.
The verdict is no. The question tends to come from American listeners, where only the one song travelled, and it dissolves the moment you look at a British album chart from the following decade.