SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59b706b4ad944e931e1594562adc85aab1698fd23c26d47abe335eba3f922a6d' 
  AND token = 'Bxl34ju3uuNc/tEBbgMstFOduHbnO22vQaMm/rYDJeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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