How to check if a column contains a given string (exactly)

I have a column with id's. I want to check if a given id is already in that column, how do i do that?
My current code is

const { data, error } = await supabase.from('my-table').select('id-column').contains('id-column', user_data.id);

const { data, error } = await supabase.from('my-table').select('id-column').contains('id-column', user_data.id);

This however, does not work.
Thanks!