SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65dd401af6ad7526f17e7647e2166b9f63f628af6465ba7b8b577776beacf408' 
  AND token = 'YnARzL/Z2em69NhEWGgbwiL54AnFrT4D/IQrqVg3JPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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