SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '813d30d676265db4bb9452b7702f68360c9ac218606eb5bf5bdcf0f1774bb822' 
  AND token = 'lajRCdDP9xHaE+qhTfI4VDt6qPlaJsnjLReoJEzm+H8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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