SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ae4532d0d506ec1f3978a92b9e513c546926fb47df08ddfc0107870e1a5a794' 
  AND token = 'WCBDG/nT23pPmO+9rKbjYRx9JSgxh389t6laGj+NPCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}