SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fb9e2561ac3ea1dd7ae046906fb8b721bae67f67473ddf1efeb82dbc7f588a9' 
  AND token = 'IDm4pPUjlJnhQoUC2DX8O0giRm5jXIfx4GEGqUUsHbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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