Erro na função

Toda vez que tento logar recebo o seguinte erro:

Warning: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, boolean given in functions_usuario.php on line 6

Function em questão

<?php
function buscaUsuario($conexao, $email, $senha) {
    $senhaMd5 = md5($senha);
    $query = "select * from usuarios where email='{$email}' and senha='{$senhaMd5}'";
    $resultado = mysqli_query($conexao, $query);
    $usuario = mysqli_fetch_assoc($resultado);
    return $usuario;
}

login

<?php include ("conexao.php");
include("functions_usuario.php");

$usuario = buscaUsuario($conect, $_POST["email"], $_POST["senha"]);
var_dump($usuario);

Formulario

<form action="login.php" method="post">
            <table class="table">
                <tr>
                    <td>Email</td>
                    <td><input class="form-control" type="email" name="email"></td>
                </tr>
                <tr>
                    <td>Senha</td>
                    <td><input class="form-control" type="password" name="senha"></td>
                </tr>
                <tr>
                    <td><button type="submit" class="btn btn-primary">Login</button></td>
                </tr>
            </table>
            </form>