SQLlite query returns an empty tuple

Question

I have a simple Python function to search a SQLlite3 dbase. Unfortunately, it returns an empty tuple. I suspect SELECT query to be inproper. The code:

def find_name_in_db(self, logintofind):
    print("List of all Users with specified name: ")
    conn = mdb.connect("users.db")
    cur = conn.cursor()
    cur.execute('SELECT login FROM users where login=\"{logintofind}\";')
    check = cur.fetchall()
    print(check)
    return check[0] if check else None

The output:

Input name to find: value1

List of all Users with specified name: []

Any help is appreciated.