SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '19e8da2ea5ba79daadcadf7970235fd88ccbcd7f86cd60d9cd4a20843fc25c67' 
  AND token = 'Ui5HQ2Kt3QDpIEIMzXRa+tVN/qGwRUT4kxux1hRg6VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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