SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afa7ad133cd1bd69dc7e5a2874c15ee91bd36a8abf1a99543359be23adf90010' 
  AND token = 'iS0+KLbk5/MyBLkoV80paQPjCwmn0Ry+AxSIuYyD83k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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