SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd56b7091e87fef97de5a53e678883667703d3153de8c20b5faeee7660bcfd9f6' 
  AND token = 'dkkfpbuMrSAIeBWKWp02Cu7Mu8qmWU/+7C5FxDYyAmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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