SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '085daaccc1deab919c8cf63d7ee32f90f16b4a4b7cead8910846c14b9a6e5656' 
  AND token = '1JxU8T9GXkJPSgKhHHO6RfuPDa6YfiS7XKZm/EllBwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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