SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb77cf1686870443328082f0ea1ad4bcedc2a380aa26d081b11840a470cd7af8' 
  AND token = 'GYpKxOMpCAxt1PRiluaBxlFmCRBYlxW7+0IWXLsQtv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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