SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5f7b6c7993b5a19329512c13fb04777d0106bc5bc6de33b519d2d96eb619d71' 
  AND token = 'Pz37sUYNsytyVDZsjte1RLEGWgRut3D/TKfiJtv07Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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