SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e87637216ca15ec6581d6a8b1e6e2fd2fb65574c97e442e6ae23e3176e6b199' 
  AND token = 'MJ8yqStArVosbh8j193i7lIsOivk1LKqZpXvFl7VJw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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