Поиск по двум столбцам

<?php
if (isset($_POST['search_buttom'])) {
$carNumber = $_POST['search_car_number'];
$stmt = $DBH->prepare("SELECT * FROM `clients_table` WHERE `carNumber` = :carNumber");
    $stmt->bindParam(":carNumber", $carNumber);
    $stmt->execute();
    $row = $stmt->fetch(PDO::FETCH_OBJ);
}
 
if (isset($_POST['search_buttom2'])) {
$passport = $_POST['search_pass_number'];
$stmt = $DBH->prepare("SELECT * FROM `clients_table` WHERE `passport` = :passport");
    $stmt->bindParam(":passport", $passport);
    $stmt->execute();
    $row = $stmt->fetch(PDO::FETCH_OBJ);
}
 
?>    
 
<div class="wrap1">
    <div class="table clients vopros">
        <div class="table-row">
            <div class="table-cell"> # </div>
            <div class="table-cell"> ФИО </div>
            <div class="table-cell"> Тел. номер </div>
            <div class="table-cell"> Номер машины </div>
            <div class="table-cell"> Паспортные данные </div>
            <div class="table-cell"> Действия </div>
        </div>
        <form class="table-row">
            <div class="table-cell"> <?= $row->id ?> </div>
            <div class="table-cell"> <input type="text" name="fio-1" value="<?= $row->fio ?>" required> </div>
            <div class="table-cell"> <input type="text" maxlength="11" onkeyup="this.value = this.value.replace (/[^\d]/g, '')" name="phone-1" value="<?= $row->phone ?>" required> </div>
            <div class="table-cell"> <input type="text" name="car-1" value="<?= $row->carNumber ?>" required> </div>
            <div class="table-cell"> <input type="text" onkeyup="this.value = this.value.replace (/[^\d-]/g, '')" name="pass-1" value="<?= $row->passport ?>" required> </div>
            <div class="table-cell"> <a class="silka" href="?page=clients&delete=<?= $row->id ?>"> Удалить </a> <input type="submit" name="u" value="Изменить"></div>
            <input type="hidden" name="page" value="clients">
            <input type="hidden" name="id-1" value="<?= $row->id ?>">
        </form>
    </div>
</div>
<form method='POST' action='' name='search_form'>
     <input type='text' name='search_car_number' value='' placeholder='Введите номер машины'> 
     <input type='submit' name='search_buttom' value='Поиск'>
     <input type='text' name='search_pass_number' value='' placeholder='Введите паспортные данные'> 
     <input type='submit' name='search_buttom2' value='Поиск'>
</form>