SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '831cd60535d35552612eb082c8780ac0d98af125d38e177d07695565c989ba92' 
  AND token = 'zmBT+OUTUYXpo8QDFKBdFMcGW2gBjYQNmikEATdU/+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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