SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cbad30d7a3cbe583692b5492a812fb90dd8b975dc6f32d481e9be96fd2961a6' 
  AND token = 'D9oeq6vcmNamZqODqHoUt9NcLgUS8h4X0vAgjarxlEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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