SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd19e287d0adb3cc10f630b70997e293ed1afe2fb9a371f7e777b28f6998a5360' 
  AND token = '/uZldFzQZFpbbGUSYngwywkkN33nszgBHVVvNCJKQ9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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