SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4544ed458c10e6e44f848762afc593f7ca87a5af679d1c676be00c997df79abf' 
  AND token = 'Wdvs2Vwyn/ON0zLcjLytgUhSCdtE57lvWw/RXvyGmWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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