SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ad1f11e896795bfa11c070f15c20a678e6c8429d39c2ee172ec1c55ea6321e6' 
  AND token = 'QxIvmBa4qPlTZcDwl3jFo6qhQpvV1YLi9xRvTPreHYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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