comparing a given variable to data in a database and checking to see if it exists

I have a sqlite db of API keys and I want to make something check and see if the given key is in the database.I'm generating the API keys using another python script named apikeygen.py. I'm using python 2.7 and pattern 2.6. This is going to be a data scraping/mining/filtering application that I'm doing just for fun and maybe have a future use for malware analysis.

I need help getting the main piece of code that we will call API.py to check and see if the given API key is in the database.

This is the code for the API.py file so far.

import os, sys; sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))
import sqlite3 as lite
from pattern.server import App
from pattern.server import MINUTE, HOUR, DAY

app = App("api")

def search_db(key=''):
    con = lite.connect('apikeys.db')
    with con:
        cur = con.cursor()
        cur.execute("SELECT * FROM keys")
        while True:
            row = cur.fetchone()
            if row == None:
                break
            print row[2]