SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7569d268c145a93cb8b4acf33553968f0fa412a275a5dd7b68e50f8e3b95c977' 
  AND token = '3PhJ3P19KStTUuXGfJYObak4dbZYoIOv9z5Hzvwq0eI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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