SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dea664f29b0bbaa38e16e1df2829993115431d6d61d023a7e57a9ffbfc093c8' 
  AND token = 'WANhYh0cGSoo6e820zOFACV2C0rcPbEkf79WoW4WHkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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