SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c97cf48c9e110a6b1e870257c483e00ebbdf537287b5c44a16e9769bdb38c8e2' 
  AND token = 'YXljg4CH+ovEfsH33uw5azF+183XK/mqZ2ln7FloS3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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