SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40edc74323842c9becd7dde8a0c7ed01329931af29deffa74af0ff6e932d05a3' 
  AND token = 'Q4nrW/XRx5XUvsWBmCzcRnnlbmTHPyd4xtKqKCJPQ5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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