SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '705cfd9df34d3416a08ad01739e652cbaac7389445020bf803fbccb31b2df9e2' 
  AND token = 'kvUZDxMD6SpqYezOYmr3Tl/mXo6gzEPhLnVgDrkWYO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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