SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65ce94b0d6218036f2a54b24dce9bb6063512c4d2910d634be98032689038c3c' 
  AND token = '6RBbATfWTVAdNL2pjEcLVwJt/o4uqdsGWYjfjo+zJOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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