$data = $this->request->data ['missing_lexicon_id'];
foreach ( $data as $id ) {
    $missingLexicon = $this->MissingLexicons->get ( $id );
    $this->MissingLexicons->delete ( $missingLexicon )
}

$this->MissingLexicons->deleteAll(['MissingLexicons.column IN' => $keys]);