SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb72fba569b9e7f48347990a48459525809de70913d24eb21055be1064986949' 
  AND token = 'Lu00jAXeyOuh7iHHtRZrtfpKO0ETqKKwt+zwnjhhj48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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