SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '981e3bf82c1830937d6f2ed4c1a307ecf57b71f1a6fa35e95200c851e1790532' 
  AND token = 'L/g9ZUJFhXTek5e1J4bX9tZzI4LhtHONtBuX0M4KhFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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