SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7841a9fa1b222d802f44232c5110e7a834b696edfa98d6729b40f9c698ca905f' 
  AND token = '7xl12vkiJng8VukWvPMzf+zNPasDgGh0Z19XnjKd/Gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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