Is the word usava the same in Brazilian and European Portuguese?

Yes

The word usava is identical in Brazilian and Continental Portuguese in terms of spelling, grammar, and meaning. It is the first-person singular (eu) or third-person singular (ele/ela/você) imperfect indicative of the verb usar. The differences between the two dialects are found in pronunciation—specifically the reduction of unstressed vowels in Portugal—and the surrounding vocabulary or syntax, but the word itself does not change.

Brazilian Portuguese Usage

1. Eu usava uma camiseta azul quando era criança. (I used to wear a blue t-shirt when I was a child.)
2. Ele usava o celular o tempo todo. (He used the cell phone all the time.)
3. Nós usávamos o ônibus para ir à escola. (We used to use the bus to go to school.)
4. Minha irmã usava muito esse batom. (My sister used to use this lipstick a lot.)
5. Ela usava uma técnica muito antiga. (She used a very old technique.)

Continental Portuguese Usage

1. Eu usava uma t-shirt azul quando era criança. (I used to wear a blue t-shirt when I was a child.)
2. Ele usava o telemóvel o tempo todo. (He used the mobile phone all the time.)
3. Nós usávamos o autocarro para ir à escola. (We used to use the bus to go to school.)
4. A minha irmã usava muito esse batom. (My sister used to use this lipstick a lot.)
5. Ela usava uma técnica muito antiga. (She used a very old technique.)