Request laravel returning null [closed]

Good afternoon guys, I'm new to frameworks but with the following problem:

the request is returning empty for my query

Thank you in advance

"select * from 'usuarios' where 'cep' = ?"

My controller is so

    public function procurapatrocinadorexecutar(Request $request){

   //dd($request);
   $dados = usuarios::where('cep', $request->cep)->toSql();
    dd($dados);

and my view like this (already has csrf_field)

@extends('template.login')

@section('login')

<form class="form-signin" action="/PesquisarPatrocinador" method="post">
{{ csrf_field() }}
<div class="panel periodic-login">
<div class="panel-body text-center">
  <h1 class="atomic-symbol">MMN</h1>
  <p class="atomic-mass">14.072110</p>
  <p class="element-name">Miminium</p>
  @include('includes.erros')
  <i class="icons icon-arrow-down"></i>
  <div class="form-group form-animate-text" style="margin-top:40px !important;">
    <input type="text" class="form-text" name="cep" required value="1305135">
    <span class="bar"></span>
    <label>Informe seu cep para pesquisa</label>
  </div>
  <input type="submit" class="btn col-md-12" value="Pesquisar"/>
</div>
@if(isset($dados))
@forelse ($dados as $dados)
<li>{{ $dados->usuario }}</li>
@empty
   aaa
@endforelse
@endif

<div class="text-center" style="padding:5px;">
  <a href="/">Voltar</a>
</div>
<div class="text-center" style="padding:5px;">
  <a href="/RecuperarSenha">Esqueceu a Senha? </a>
  <a href="/registrar_com/procurar">|Seja um Afilido, Procure um Patrocinador</a>
</div>
</div>
</form>
 @endsection