SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8be618b401861a9ff6c224770202dcdc4e5ad4ce36a966f774b2d6af85580d2f' 
  AND token = 'v8TfuH8PFM6TBWNfNpCvoUVhCDLGmu2UrGIhUPufQZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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