<?php

$fruit_names = [];

$stmt = $dbh->prepare('SELECT id, fruit_name FROM fruits');
if ($stmt->execute()) {
    $result = $stmt->fetchAll();
    $result_count = count($result);
    if ($result_count > 0) {
        foreach($result as $row) {
            // decrypt and push into array
            $cur_fruit_name = $row['fruit_name'];
            try {
                $decrypted_fruit_name = Crypto::decrypt($cur_fruit_name, $user_key);
                $fruit_names[$row['id']] = $decrypted_fruit_name;
            }
            catch (Defuse\Crypto\Exception\WrongKeyOrModifiedCiphertextException $ex) {
                // Either there's a bug in our code, we're trying to decrypt with the
                // wrong key, or the encrypted credit card number was corrupted in the
                // database.

                // ... handle this case ...
                $fruit_names[$row['id']] = "failed to decrypt";
            }
        }
    }
    else {
        // empty result handler
    }
}

// then you can search for what you originally wanted
$requested_fruit_name = $_POST['requested_fruit']; // say apple
$match_found = false;

foreach ($fruit_names as $fruit_id => $fruit_name) {
    if ($fruit_name == $requested_fruit_name) {
        $match_found = true;
        return $fruit_id;
        break;
    }
}

if (!$match_found) {
    return 'match not found';
}