SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '94259030c296aacb7f0d92fd75e073a9a55ea9c56b795a7afe0fae134ee7c906' 
  AND token = 'vVJfM1vyoS6D4Pd4Wuajk2sy7N4kIU+DT4wXd+WDw8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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