Rinse the brown rice and cook according to package directions. Season with salt and black pepper once tender and keep warm.
Place the chicken thighs in a bowl and add the smoked paprika, ground cumin, dried oregano, garlic, honey, olive oil, and salt. Mix until the chicken is evenly coated.
Arrange the chicken in a single layer in an air fryer basket. Air fry at 375°F (190°C), turning halfway through, until cooked through and lightly caramelized, reaching an internal temperature of 165°F (74°C). Let rest, then slice the chicken.
In a bowl, combine the arugula, tomato, cucumber, olive oil, and lime juice. Season with salt and black pepper and toss gently.
Combine the sparkling water with lemon slices and add ice cubes if desired.
Serve the chicken over brown rice with pickled onions, alongside the salad and lemon sparkling water.