Why is LIKE request processed faster than EQUAL?

Question

MySQL

We have a simple table for ~ 3 million records.

CREATE TABLE `MTRIVI` (
  `id` int(11) NOT NULL,
  `numero` varchar(45) NOT NULL,
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

ALTER TABLE `MTRIVI`
  ADD PRIMARY KEY (`id`),
  ADD KEY `numero` (`numero`);

We create two requests.
1. SELECT * FROM `MTRIVI` WHERE numero =1000410001 LIMIT 0 , 30 ; 12 total, Query took 9.4297 sec

2.SELECT * FROM `MTRIVI` WHERE numero LIKE '1000410001'; 12 total, Query took 0.0009 sec

All the time I thought that like query is slower than = .
How to explain it?

Answer 1

because in the first example, the comparison is not with a string, but with a number, hence the type casting and the query goes past the index, which is clearly displayed in the plan. key column