SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21c552ab30b7e068e4ff8aefbfc62b1482021dde3892fd2aa128fd0d0e5192ba' 
  AND token = 'gvuqYLFXevL689BZAN8VlV4pSbuLVOhMZGq8dqmndYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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