How to check if a row exist in the SQLite table with a condition

I am using SQLite local database in my software. I want to check if a row exists based on the giver values of the row. for example : "SELECT * FROM ftp WHERE Host LIKE '"+ host +"' AND Username LIKE '"+ username +"' "

But I want to get boolean result so if finds the record do something and if not do something else. Hoe can I do this?

here is what I tired but it is always true, since it check if quesry runs and not if it returns data.

public void ftpTableCheck(String host, String port, String username, String password){
        try{
            String query = "SELECT * FROM ftp WHERE Host LIKE '"+ host +"' AND Username LIKE '"+ username +"' ";
            PreparedStatement pst = conn.prepareStatement(query);

            if (pst.execute() == true){
                System.out.println("true");
            }

        }catch(Exception e){
            e.printStackTrace();
        }
    }

Any idea how to fix it? Thanks