SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c67725607324614c9ab76d4b30e1500947af7a19b0ec12a0ccc008bad4aeeeb3' 
  AND token = 'h5lYGRRxdWQFK2AB2CNYbVL786T99zBhY/51D4ZVdKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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