SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47b516f175305db91a355601ae69586b115b2bf11077886e6940aca3ed60eb28' 
  AND token = 'JKUzhnYXSyKa9F+sAyrV7fGVXAexVpRqMABlTDJ19Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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