You can achieve this using a theme:
in styles.xml
<style name="AppSearchView" parent="Widget.AppCompat.SearchView" >
<item name="android:textSize">60sp</item>
</style>
And using a SearchView
<android.support.v7.widget.SearchView
android:id="@+id/searchView"
android:layout_width="350dp"
app:theme="@style/AppSearchView"
android:layout_height="80dp"
android:layout_marginTop="15dp"/>