SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e268a8da783a6f03df83fc8c775b52b430675feefcd7f26586e7c20db498c130' 
  AND token = 'x9WdBOOKsFqTBhSDIQbyZm9THCHmvyrDQcfSdQhj23w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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