SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '480ea8712f00c04f7805aa088dd29c7b5064d1bd9d54d402720fa1397902c4e7' 
  AND token = 'Pw5w1T2/9xrzCvWdFJVmfJMZ/Xl6bukxwBpiIkZuN+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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