SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b92a4f9f4f3a8c761733127358a32c138d779b7d1ef55d1a9a4ae3c26d4050f' 
  AND token = 'iiIWMUq+s9shuyzfUpBuQrNILy1sp6sXvJ7IOOQn/Mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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