SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395e48e410c9b364b524062c57de7666a8abf9fdf8857d4453387f462bfbcdb9' 
  AND token = 'WKpxS4bpacoAZhyA74lVykIOgA04G85wJBGkZLcKJiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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