SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af2055920a3482363240088c0063792aedcde5279aaa7cd7b47440e510f3d783' 
  AND token = 'm+gx+uFW6a7RRFqmojqfq2mBrYhpPXuiv0KvZtvWhu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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