SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a38ff0b9342e5f0e9b9eee86f24688836444f938a7e8ef5c0d7af366e40ec035' 
  AND token = 'i8lEBaWRsBs7W0fAks/kBwFXWnxwPDX6o0qB7d/btMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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