SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '40b5d8e6b6f3ec1f28c04082e0cd010681631ff867779a2726d0329eddbfeb8f' 
  AND token = 'Q5rJ/RbUvXX9yH3HBLhE0+zwCli3/KHc8kJYvI8Zna0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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