How to store a 64-digit key of alpha numerical values into MySQL Database
Storing:  Use a field with datatype BINARY(64) or CHAR(64) CHARSET ascii COLLATE ascii_bin.

Generating:

This is not an SQL question because it should not be done in the database.  It should be done in the UI layer that receives and checks passwords, etc.

So, given that you should write this in Perl/PHP/VB/Java, you have much stronger tools with which to generate the corporate password.

Of what use is a password that everyone knows?  As soon as a disgruntled employee gets fired, the password may become known to the world.

I'm serious -- some things do not belong in SQL; instead they should be in the code that access the database.

But if you must do it (for the class) in SQL, consider creating a table of the possible characters, one per row, plus another table of (at least) 64 distinct integers.  Then use a JOIN, GROUP_CONCAT, ORDER BY RAND(), LIMIT 64, and probably a subquery to get the INTs.