SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c5f5c7e99ba5c6d58327f7ced25b6ff9b4137548311fd5e071a049b4e4cae3c4' 
  AND token = 'CLg5sU69kMU7BYtU2/Qhh4TXvq7T/a8XmlZ8LOH85Kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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