SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11edc84478b6caa8158e4b3474413df2cec5507cafb410a2f3f6eed86cbd8e97' 
  AND token = 'f7QHphaft3STLXHszEM09ebDh9Yo5brKjqqjwLzhpWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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