SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8da3508401d0463cae6959e507efa9529792b0414523ec2f6313aef196da7c1' 
  AND token = 'WZJIliEqz9uX6OveQNy4wGGrmGh9LX2jhDH6Y17VZKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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