SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d46c7765ffbfb308f3b8912b2e69e8caf066806983fafe56210f522d48652ac' 
  AND token = 'xfXnVqTU+X42Bm+26Cphqd58IILz5UwQ2zdAYBY4ao4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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