SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '924e59726df04fa2544185fd43c6313438949aff882c3950535f92a64b2894a6' 
  AND token = 'CdCfZDddTPj4egiaV26/XH4Izoj82BcRCIeeFknpOEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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