SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de09bc766a3ef985f16eb756fb57edad56459526bc65d4db6cfb320de6f13085' 
  AND token = 'Rhz6By0vIrW+cbTizYPHJXU6mHkoG8a1320DeiBIuX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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