It is common behavior in most programming languages to interpret leading numerals as a number when converting a string to a number.
There are a couple of ways to handle this:
Use prepared statements, and define the placeholder where you are putting the value to be of a numeric type. This will prevent strings from being put in there at all.
Check at a higher layer of the application to validate input and make sure it is numeric.
Use the BINARY keyword in mysql (I'm just guessing that this would work, have never actually tried it as I've always just implemented a proper validation system before running a query) -
SELECT *
FROM table
WHERE BINARY ID = '32anystring';