SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9b214bab86e95661b2b1a4801e60a38d169fae329ab25861415cc8209a867ab' 
  AND token = 'v5nxwmb9kaVGHpleF118XWk7qWX/KBFSsdKlbtJ9Z9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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