SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d099c54f1dcffcacf985f3eb779d064f32b34c1a44786818b9820ee6d62ebe9' 
  AND token = 'XsCE0SQPtrlMgCAbmnrl9SQBbJyQLko6+DAq6odWK8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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