SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8360284b46669cd057289269181d02df3514201b5bccea9f13e9757781bdf52e' 
  AND token = 'Tw4OBzzEt6hWBGZOgY/Lv52wqmqfFLlDG8JBwLI7B74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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