SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eedce78ff3f638a78d5b0aaccd5948c1ff3723315ec913b66acfab0794821c5a' 
  AND token = 'ZKhGW1QMRR+ONTklXmeO6IFqb4vNUJqiDGILXGDaXig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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