php - PHPの配列で特定の値を検索してキーを取得する方法

Question

値 id_img=17 で検索してキーを取得したいだけです。これは配列です：

$array_test = array (
0  => array("id_img" => 18, "desciption" => "Super image", "author" => "Person 1"),
1  => array("id_img" => 17, "desciption" => "Another image", "author" => "Person 2"),
2  => array("id_img" => 22, "desciption" => "The last image", "author" => "John Doe"),
);

ご協力いただきありがとうございます。