Check whether GRANT EXECUTE TO user or role was applied

I found where it is stored, so until someone posts simpler answer, I'll keep this code snippet at hand for case of checking:

DECLARE @username nvarchar(128) = 'user01';

SELECT COUNT(*) FROM sys.database_permissions 
    WHERE grantee_principal_id = (SELECT UID FROM sysusers WHERE name = @username) 
        AND class_desc = 'DATABASE'
        AND type='EX' 
        AND permission_name='EXECUTE' 
        AND state = 'G';

Result 0 means negative answer, 1 means positive.