SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934e6ce19e5cf690f4fa478af67a1e9435b2f041e0ac4f1b29ec5baf0569241d' 
  AND token = 'zkimEEjmeSXEbO5YhXQFoExqixosF4c1o8Q35hUQF0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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