SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a580996ef742f7971e885dbc15c6f87174423d478d2b1d4b8bef8c78daabd5ab' 
  AND token = 'BLUYnQPrT8CAadxeg5xikvY2/TitNHRIw09uX5cFOjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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