He achieved some standing in his profession and was elected in 1926 to be President of the Society of Incorporated Accountants and Auditors, a position he held until 1929.

Keens was first active in local politics, being elected a councillor for the Luton North Ward of Bedfordshire County Council in 1901.

He was a Deputy Lieutenant of Bedfordshire and for a time was Chairman of the Lee Catchment (later Conservancy) Board, responsible for the waters of the River Lea.

During the crisis of 1931 which resulted in the formation of the National Government under Ramsay MacDonald, Keens favoured the Liberal Party's support of the coalition and sought election as National Liberal for Pontypool in the 1931 United Kingdom general election, but was unable to beat the sitting Labour MP, Thomas Griffiths.

He never stood for Parliament again but chose to support publicly the National Conservative candidate Michael Beaumont at Aylesbury during the 1935 general election.