SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28bdd695c279bf775485973e4065fb63b9213223679cfdc3e6ff367505ab4a1f' 
  AND token = 'joB7Q3OqhGHl8HQEB9CT+8oCDenuUQh4SskGhq0KaEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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