SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbebce03598cadfaf8d90532063dfc6edca31cfb3ad94deed07e9f0a6da1e718' 
  AND token = 'wfHIyprRGn36fcNltllW8yfS7TPrsO6RBgZdyk1mt3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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