SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b6df5b338053ee30bd152c57fd3db1e90442c0b9aa6f759a94cfc5a242166fb' 
  AND token = 'KuDkUyBhsCAnUJHPHBpLUbI/oexCg61Djq/JCqCbVEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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