SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5a27bf4b75824f8c0bff98a062582e413590179695babd3d9d55aea347ad00ea' 
  AND token = '6PGoEgO8DOvvsBH8Pmn1DZu2QO/rqprtDA/RybAItTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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