Unavailable exception while trying to retrieve data from Cassandra

I have a Cassandra DB and am creating a column family as follows.

CREATE COLUMN FAMILY users
WITH comparator = UTF8Type
AND key_validation_class=UTF8Type
AND column_metadata = [
{column_name: username, validation_class: UTF8Type}
{column_name: city, validation_class: UTF8Type, index_type="KEYS"}
];

I am inserting data into the column family using the following in node.js

var cql = "INSERT INTO App.users(KEY,username,city) VALUES (?,?,?)";
cassandra.execute(cql,[json.username+(new Date().getTime()),json.username,
    json.city], function(err, rows) {
  if(err) {
    console.log(err);
    return 1;
  }
  return 0;
});

This executes properly, but suppose I use cassandra-cli and run

 get user where city='NYC';

I get an unavailable exception. The following is the CQL query which I have in my node.js script which throws the same exception.

var cql = "SELECT notes,heading FROM App.users where city=?";

Do you have any idea what I am doing wrong? I have made a secondary index on the city column, I hope that is correct. Thanks in advance.