SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b95324aff267fdbfdaff1f92cae4c084909510a10205f930e3ec5437e53e9dd' 
  AND token = '8EpxmqWD5hRglt0DMaKfqrVLAyY5bli5GiP+cwhRb0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}