SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb0f1270e2b61396369bae639d6305f469ad022a05347edab5d03c44a8d4ae09' 
  AND token = 'mgfIYixSV2IZSsM/eXqG+R625QnQrm5Dpsm+E8ZDiFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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