SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00189c37a1dff2d725a976f813daf3df87a8237595ad63259c099932858cc1da' 
  AND token = 'W5KEtWnCdR3zvcI6PM4b2WCpX84XlghQdNG6xsahFfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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