SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4098d604560d9f48d547620643b048ed9bc5301543c67181162d52444a16f714' 
  AND token = 'p3CBmAgVXHtr/oaydnwmNrIIrViwUaLhV3qFxFcJO0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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