Hi, I have a Huawei Ascend Y550 and its on fast rebboot rescue, how can I unlock it?

[AC Question]

hi, I have a huawei ascend y550 and its on fast rebboot rescue, how can I unlock it? please help me

when it turns on it goes straight to fastboot rescue and a message appears saying to connect usb cable to a computer.
at the end says PHONE LOCKED
please I need help, what can I do?