SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5660e2cefdcaca98db25be996cbb6209394a52af95467443129557005868b181' 
  AND token = 'QUbnO2TgxSTLNo/tK5/gfAyXFfP7fexP80S/F5jnlG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}