node js function cycle in different files using asynchronous callback

Question

i have a problem regarding cross-file calls and their lifecycles. I want to query the dynamodb for a username to login the entered user.I query in an external file to minimize queries as i need to use the data in another file too. The cycle seems to be off though and I really don't know why. The query call comes after the POST / login although the input in the form is available earlier. It would print the queryparams before the POST/login call too if i'd call a console log on it. The callback does not wait for the actual data. I have browsed other posts containing information regarding asynchronous callback functions but couldn't figure out why the callback completely ignores the query function. The problem is not the communication between browser and server but rather between files/classes in the node script. The data is available for query before the post statement but the query gets executed after. This is What can i do to prevent that?

the console output (for debugging purposes) is:

GET /stylesheets/style.css 304 3ms
callback
undefined
POST /login 500 38ms - 280b
querying ...
information found
[queryResponse Object]

the query file:

const AWS = require("aws-sdk");
var exports = module.exports = {};
const dynamodb = new AWS.DynamoDB({
  apiVersion: "2012-08-10",
//   accessKeyId: "", //TODO
//   secretAccessKey: "", //TODO
//   region: "eu-central-1" //? TODO
  //testing purposes
   "region": "us-west-2",
  "accessKeyId": "abcde",
  "secretAccessKey": "abcde",  
  "endpoint": "http://localhost:8000"
});

var dataAfterQuery = null;

exports.query = function(queryParams,callback) {


/*prevent unneccessary queries*/
var queryNow = dynamodb.query(queryParams,
    function(err,data) {
       if(err) {
          console.error(err);
           return done(err);
        }
        console.log('querying ...');
        if(data.Count > 0) {
            console.log('information found');
        } else {
            console.log('"' + JSON.stringify(queryParams) + '" is not in the db yet');
        }

        dataAfterQuery = data;
        console.log(JSON.stringify(dataAfterQuery));
        return dataAfterQuery;
        });



    if(typeof callback == 'function') {
        console.log("callback");
        callback();
        return queryNow;
    }
}

/*function to recieve queried data*/
exports.getQueriedData = function() {
    return dataAfterQuery;
}

the login file:

module.exports = function(passport) {

  passport.use("login", new LocalStrategy({
      passReqToCallback: true
    },
    function(req,username,password,done) {

      var queryParams = {
    TableName: "users",
    KeyConditionExpression: "username = :user",
    ExpressionAttributeValues: {
      //username entered in jade form
      ":user":{"S":username}
           }
      };
      queryFile.query(queryParams,function(err,data){
      if(err) console.log(data);
      //console.log(data);

      //kommt vor information found?
      console.error(data);
      /* response can only be null or not null*/
      if(data != null) {
        console.error('error, more than one user with username: "' + username + '" in the db');
        console.error("Entries :" + data.Count);
        return done(null,false,req.flash("message", "more than version of the username in the db"));
      } else {
          //only one user exists in db, query for username was successful
          var parsedQueryPw = data.Items[0].password.S;
          userAfterQuery = data.Items[0];

        //checking if entered password is wrong
        if(!isValidPassword(parsedQueryPw, password)) {
        console.error("invalid password");
        return done(null,false,req.flash("message","invalid user-password combination")); 
           }          
      //successful login - user and password match
      console.log("login successful");

      //return user object for serialization
      return done(null,data);
     }