SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcfac96d836d48b8c19b842486ead8b9b0e72b32f22a0a59d90d38675a7c8a3d' 
  AND token = 'Zlp/rG6ZDReBvC7FXq76zgJeb1fxd5bBes/KVQAaoUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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