SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddf2d9f6c9ba095a625d2827bb877371826beb569f8387b145b28ae21f55cc55' 
  AND token = 'gHcPGuyO2Jh4l+bJYGNn/vnUygD8MvtG/1CC1JNaw/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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