SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb97db7724e34b7590e9dda616b99c74b2f3b0d38e2b6100000be5a8ed5609f0' 
  AND token = 'ovUXAraoldOeXknVTsgYzRgLlJG9jJX+U6VUj8wKJl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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