SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca27623599bddd91d8354665a05c9417ff64273653bf71354a35b2be542e4c54' 
  AND token = 'zVBsZ9+hkRzv3X4VqYItNR6guu/8XXjLFqdFcAULcxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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