How to determine if a column already exists in a MySQL table before altering the table to add it?
You were on the right track.  Add one thing before your code:

USE YourDb;  -- You need to be in _your_ db to make `DATABASE()` work right

SELECT COUNT(*) as col_count
    FROM information_schema.COLUMNS
    WHERE  TABLE_SCHEMA = DATABASE()
      AND  TABLE_NAME = 'mytable'
      AND  COLUMN_NAME = 'status';