SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28f8dfc7a231bee0937714a7df4515250b32b93b07fc24f3aa5c0eb5d9925dc7' 
  AND token = 'IYKnfZEZjENvtOoPID3wlertTuie0CgGxdin+QLKUzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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