SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3404353a4033c32145a216940dc2f6b044618a161f7ecf0e1a09417cf5eac8d5' 
  AND token = 'WBLGLV/I+mAIyQlwJzqJsf0/8WYEAuSjoSnJmdoXNvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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