'lay less than' is correct and usable in written English.
You can use it when you are talking about a number or amount that is lower than something else. For example, "The cost of the new product will lay less than the competition's."
Dr. Rona's creatures lay less than a mile way.
The Thames was one of the filthiest rivers in the world, laced with industrial waste and raw sewage, and the tunnel lay less than twenty feet below its bed.
Most threatening, Archduke Charles' main army lay less than a day away; in size alone, it could overwhelm him, or, if he withdrew to the west, its position cut off his avenue of withdrawal toward France.
It took almost three weeks to find Langley's body even though he lay less than 10 feet from where his brother had died of starvation; he'd been bringing Homer food when he was crushed by a booby trap constructed to keep intruders at bay.
Most of the land lies less than 130 feet (40 metres) above sea level.
Nearly the entire North German Plain lies less than 330 feet (100 m) above sea level.
It was lying less than a quarter-mile from the highway.
Tikrit, believed to have been taken by the insurgents overnight, lies less than 200km from capital Baghdad.
Aleppo, a major manufacturing center that lies less than 40 miles from Syria's border with Turkey, has been a traditional area of resistance to the Assad government.
The Egyptian capital lies less than 100 miles from North Sinai, where Isis affiliate Wilayat Sinai has been targeting soldiers and police in a bloody insurgency.
If you come to Vamos in summer, the sea lies less than four miles away, with sandy beaches complete with water-sports facilities at Kalives and Georgioupoli.
