<?php
$array = [
    'name'     =>'vasya',
    'city'     =>'Kazan',
    'age'      =>18,
    'param1'   =>23.5,  // <-
    'param2'   =>5,     // <-
    'param17'  =>11,    // <-
    'param9'   =>0,     // <-
    'paramid9' =>2,     // мимо
    'level'    =>3,
    ....
]

<?php
$result = array_values(
              array_intersect_key($array, array_flip(
                      preg_grep('/^paramd+$/', array_keys($array)))));

$result = array_filter($array, function($key){
                 return preg_match("/^paramd+$/", $key);
             },
             ARRAY_FILTER_USE_KEY);

$result = [];
foreach($array as $k => $v){
    if(preg_match("/^paramd+$/", $k)){
        $result[$k] = $v;
    }
}