Question

I know its supposed to improve performance and clean strings, but lets say there are no variables?

Might just be a

SELECT COUNT( `column` ) AS count FROM `table`

1. Should that be prepared?
2. Is there any case that a SELECT statement should not be prepared?

Answer 1

As a general rule, you should prepare statements that take variables from somewhere else. Usually this includes INSERT and UPDATE statements, SELECTs and DELETEs with WHERE clauses, and stored procedure calls with arguments.