SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ac943416a7cb827de66ed9160de5c946c2ae0d28c1f66a863ebb0facced7902' 
  AND token = 'VjUMKahoqqutbxPQtrnZhHUWvA9awOLnCK+HVqtRtWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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