SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcb226a9415685a979c63707afc019408a35f1ef572725ff22524c134774e6de' 
  AND token = '7/HMizTpc7JB2Bn9zWzBApHuEIvcwLCGaQaXLCh0spA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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