<?php

$food = [
    1 => 'яблоко',
    2 => 'груша',
    3 => 'арбуз',
    4 => 'морковка',
    5 => 'огуречик',
];

$keys = [4,5];

$filtered = array_filter($food, function($food_key) use ($keys) {
	return in_array($food_key, $keys);
}, ARRAY_FILTER_USE_KEY);

print_r($filtered);