SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6164661bfb73b8615b7074f3bcc621de7b460a4ef3e5b463831c3b1587fd4edd' 
  AND token = 'ilUPf+MenDpL+8bayg0Lvz7ZfRBIVgoZSkMoATXIxvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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