SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '258b082c269656f7f47d9458878f7bd52c43ab144a83d8f8a8b071bf01c9a44c' 
  AND token = 'Z+jqrVWkg3T5k6hLlGZygeQNDyOgLkLHry5BrTHmZz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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