SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0530f919655cb9f101421b797a060871870f60d289eb89456a4ee42e714cb838' 
  AND token = 'uhiCtaK3Brr+ALLgN83fUq+zjCyMFxX2bGA9whPDNVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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