SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '491712f212a02ef9a3c34ea70d86451aa4d6de5b4fd8023041af240498659a9c' 
  AND token = 'Wllaa0z6fZBesAj3bnjyMtKlcw5TVTNZDKpc5XmYlHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}