SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '487958e6d80aebb203d34b33833a6646b37b0195b4de85ead979ba769c2b5cf7' 
  AND token = 'boUsZaWrI1mH/PpBCSHdDVO58/L8VGD4JXU2gAzZKfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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