SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d553c3706b7d81d8d02fabdb45220ce347971534b844dccdd1ba3f13799eaa4' 
  AND token = 'xLijvQlnPfvyHd8i1tTwLObCZ5uSQgo7/abaiwG8+aQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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