SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd7f031848ca85d070555e9fcb3a1920b74f6182ca5a23f885f26063533d450f' 
  AND token = 'BgzCy1+vFzj1WZcm/8RkptXSVNdqYgYPwjHQkyazwng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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