SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c46707cc856c9e9f5b798bba191e5f059045f46b6c0d50bc3b7580f7552894d8' 
  AND token = 'j4ifnSVjW0hg775WPY+P9gWBDa3xqpEY7KOwZK2IglU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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