Asking if a single-celled organism is conscious kind of feels like asking whether quantum theory is statically typed. Like applying a descriptor from one category to objects in another.
> There are few explicit defenders of panpsychism at the present time. The most prominent are David Griffin, Gregg Rosenberg, David Skrbina and Timothy Sprigge.
https://plato.stanford.edu/ARCHIVES/WIN2009/entries/panpsych...