SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bb4451b94bb58183a1b343ed6075e4c8f63697040fc04b95adb19189d4cc761' 
  AND token = 'Mepz5F5GcTzu5V3YuisI95BubLwWaAta5l75VSTVapo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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