SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcc4bfb41fbdbfc205b7159ddfc4948496dd478eae1faae7f0b15a504bcf5839' 
  AND token = 'aWaetTVbnhcvBTz3x4DscDLMiSKlX3xSjFtNBQrwDzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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