<?php

function removeduplicateKeys($data){

$_data = array();

foreach ($data as $v) {
  if (isset($_data[$v['ean']])) {
    // found duplicate
    continue;
  }
  // remember unique item
  $_data[$v['ean']] = $v;
}

$data = array_values($_data);
return $data;

}


$arr =array( 
"0" => Array
(
    "ean" => 6900532615069,
    "productPrice" => 1140,
    "productCount" => 5
),
"1" => Array
(
    "ean" => 6900532615069,
    "productPrice" => 1140,
    "productCount" => 50
),
"2" => Array
(
    "ean" => 6900535364122,
    "productPrice" => 1140,
    "productCount" => 50
),

"3" => Array
(
    "ean" => 6900532615069,
    "productPrice" => 1140,
    "productCount" => 10,
));

print_r(removeduplicateKeys($arr));