SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fa49b1aab64fe95093754dc228a696650ba2aa6c863186726cfd1bf44f75695' 
  AND token = 'c28LltHmtrmJISmSVv0YP0O4hongOkHKtXOxqQ6iJVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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