SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aee432cf8b269d8f805a4e8b20540e67f454ea51767dae5afdb6cc136a958db' 
  AND token = 'wVjul9SA3cLhWfvByVt0DR7pQpJgnChYrWg0aFx2ImE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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