diff --git a/src/alumno/student.controller.ts b/src/alumno/student.controller.ts
index 3db9341..d0354be 100644
--- a/src/alumno/student.controller.ts
+++ b/src/alumno/student.controller.ts
@@ -21,13 +21,13 @@ export class AlumnoController {
     return this.alumnoService.create(createStudentDto);
   }
 
-  //@UseGuards(JwtAuthGuard)
+  @UseGuards(JwtAuthGuard)
   @Get(':id')
   findOneWhitSancion(@Param('id') id: number) {
     return this.alumnoService.findOneWhitSancion(+id);
   }
 
-  //@UseGuards(JwtAuthGuard)
+  @UseGuards(JwtAuthGuard)
   @Get('sancion/:id')
   findOne(@Param('id') id: number) {
     return this.alumnoService.findOne(+id);
diff --git a/src/mesa/mesa.service.ts b/src/mesa/mesa.service.ts
index c089e2b..03b63b7 100644
--- a/src/mesa/mesa.service.ts
+++ b/src/mesa/mesa.service.ts
@@ -38,15 +38,42 @@ export class MesaService {
     });
   }
 
-
-
   async findAll(): Promise<Mesa[]> {
     return await this.mesaRepository.find();
   }
 
-
   async findAllActivo(): Promise<Mesa[]> {
-    return await this.mesaRepository.find({ where: { activo: true } });
+    const mesas = await this.mesaRepository
+      .createQueryBuilder('mesa')
+
+      .andWhere('mesa.activo = true')
+
+      .andWhere((qb) => {
+        const subQuery = qb
+          .subQuery()
+          .select('bitacora_mesa.id_mesa')
+          .from('bitacora_mesa', 'bitacora_mesa')
+          .where(
+            `TIMESTAMPDIFF(
+              SECOND,
+              NOW(),
+              DATE_ADD(bitacora_mesa.tiempo_entrada, INTERVAL bitacora_mesa.tiempo_asignado MINUTE)
+            ) > 0`,
+          )
+          .getQuery();
+
+        return `mesa.id_mesa NOT IN ${subQuery}`;
+      })
+
+      .orderBy('mesa.id_mesa', 'ASC')
+
+      .getMany();
+
+    if (!mesas.length) {
+      throw new NotFoundException('No usable table found');
+    }
+
+    return mesas;
   }
 
   async updateActivo(id: number, updateMesaDto: UpdateMesaDto) {