SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ca67b094951eb927e22cbf70fc0710f52be6ec4b70a39f7468eefe83fd81f4f' 
  AND token = '/qpIJP2uRMFr3314keg3JXXEoLEG3WgbQXZYLFcLEMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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