Write too slow after adding Trigger to MYSQL Insert

When I insert this trigger into my database there is a slowness, coming to give this message:

Errormessage: Lock wait timeout exceeded; try restarting transaction

My trigger is as below, the cod_prod field of the products table is indexed correctly.

DELIMITER //

CREATE TRIGGER ESTOQUEENTRADA 
BEFORE INSERT

  ON estoque FOR EACH ROW

BEGIN

  UPDATE produtos SET quant_estoque = quant_estoque + NEW.quant_prod WHERE cod_prod = NEW.cod_prod;

END;//

DELIMITER;