SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2900b37573ca995326d439488b540b6719f0feac14c8b5a040178f301778e090' 
  AND token = 'HQbVX/0YgGT4E477TvxOW4+FwDQSqawSkcXxvDUcCys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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