SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b10a17292963cde9594ccf68daa14d044abddbf2be3ecd8b375ae7c15daca3f' 
  AND token = 'y41v0rw0RIe6BwMvepnIhXy6aJo/R8HdXaJAgqy6SyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}