SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da6424b1738de96b5bf96e30b64be3d92fcbf30b44a26fc3aa5debbd46d6416d' 
  AND token = 'VRHrjnliQZuvzhZhPxvUSWRHFVKPtW8pGNyGnkqAqfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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