SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e304968ddf6df50e02a2796c38a730bc1e55b4a9b39f89ab85799969632e339f' 
  AND token = 'Cb0sMImxZ51wXIdM9YGB/wLGASNkw9zQy4YhkWddfiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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