SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94d6948833bed407f66ebc8189c274ea66af6d70f321bc238c4389274da42648' 
  AND token = '97JmhViu1PymzYoGItiipILPNqjX/wlriTIJGCSPeks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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