SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f5473b582f93ee042560868dd2ab799de7ba780d0264a1294a1e4de17841f4f' 
  AND token = 'ng4LpLhJNMDeOLfHupkjpoTGSqNNkP1LtoQIEubJm9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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