SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db794b4ebb586528ce20f3f7f26b749a43bb40f5cfdf6ee7c64387be7a731c46' 
  AND token = 'iFaUGZMvRIMx6FwBiYgKWfGeP7J8pXorN4O4prjnlI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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