SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f19be0b6dfe64dabf004a6f073c27d16b092c1136f27d8271b54a46deafc7013' 
  AND token = '94Xbfn9tQm9GHfDhqpNoz+q8GUKOP/dC9EqflvBBj5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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