SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d2dde5f027e1e82d8ae46973232164d7b86b16a532f96d5071f17ce50db163b' 
  AND token = 'IIFo18qoEnfObSKPIiYwBSm3cp1sxUybW5vWNfJ/GgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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