SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd76696639d7278d2ca610a6470529110172ea888011d21568706e54ad60c1e5' 
  AND token = '63AlmbCkUmhekXssOn0lVORXnRIpaQWPDvD5N+s8g9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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