SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '673bcd40f33cebcdac651705b9b65845bea97b598cffacd991563beb454244e9' 
  AND token = 'F0cDj8IUL9TxpGrvOCTPIcEYckkIVOq/yZwkoLAqPDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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