SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afee052103c56b836717d0dc2768f65d3bb22374f076972ad327ddbb4b4d5caa' 
  AND token = 'HSDZ/OrwZP1h87GpBUM/XvRmNs+k1sDeD5tg/t+BoV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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