SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e17fc4a54708cd4f206c7ff5f54553d5bb308389958b3c170d53cb55bff3fae' 
  AND token = 'uwGWMPVrqNdtdda3s/2GIFWat6Z2nC6KwTwZDxAETV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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