SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a4cab6d54d1ccafd4980f4d393289a61ad5b62ae99b9d0a1a07a442372773d8' 
  AND token = 'vbdHKBYl4nZE9TmAGjgb+c3tjzka0wVPe4U5Ewa08y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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