As a result of Bug 37508, it isn't possible to use the reports module to identify which users are MFA enabled using e.g. the following SQL which used to work:

SELECT 
  p.borrowernumber, 
  p.firstname, 
  p.surname, 
  p.cardnumber, 
  p.branchcode, 
  IF(
    power(2, 2) & flags, 
    'yes', 
    'no'
  ) as Staff, 
  IF(
    power(2, 0) & flags, 
    'yes', 
    'no'
  ) as Superlibrarian 
FROM 
  borrowers p 
WHERE 
  p.flags > 0 
  AND p.auth_method = 'password' 
  AND p.dateexpiry > CURDATE() 
HAVING 
  Staff = 'yes' 
  OR Superlibrarian = 'yes' 
ORDER BY 
  p.branchcode