SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '153fc23028ebe71fdfa71d42d7cb6ff270eb515fdc3a19dbed2c3c985b7422af' 
  AND token = 'l4OwoxFHTvul+J2g5tisUGVKJjYAWLBz/CLShBg3S78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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