SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f5b0e6c74846af5c9bf7d9824571a0d61bd06c3b3c31b3edb2e1300f7024b27' 
  AND token = 'jhrINuNIShuTmbHXvxISvZvEK1+ltNzrqKLTf2fY2mU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00087

JSON explain

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