SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c9e9f8566b3192b75e3aaf2421c9d7ec370a3b2bf9b73f8fae4b6de25806f45' 
  AND token = 'KlHwumStGtKzapxQLpBwH0dtmIsjxmPVsvNLYQyL2/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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