Optimizing MySQL Queries

[Costas]

//Use the EXPLAIN statement to see how the MySQL optimizer is executing your query:
EXPLAIN SELECT * FROM users WHERE user_id = 1;

//Use prepared statements and parameterized queries:
PREPARE stmt FROM 'SELECT * FROM users WHERE user_id = ?';
SET @user_id = 1;
EXECUTE stmt USING @user_id;
DEALLOCATE PREPARE stmt;

src - https://www.qubitsize.com/10-tips-for-optimizing-mysql-queries