SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '415e09e29061149768830cfe23d6c493cdbcd9937552c4d3a2dff861cc1d518f' 
  AND token = 'qJdAXBUp+2fD8kjlVO/4Tq0L1Z5+s1Pg4dahWVTBvXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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