SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '857fe9a436bc190d6cbc9756f0d96a8f69902b17e8f5be28a5b8c87c0c7d9e9f' 
  AND token = 'wvVnB28Suynho4sVNSwlgS4hKR328p+eGYXtTGMKKl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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