SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '70318ee27c6b63a5b777f30dd88677f94c9161287d93e682b122794b79df6ad6' 
  AND token = 'ZWrn27eXMF/MN0fgh0GFtMqfGXeAMYzuH/+qwYvR+/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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