SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46307f66a00f8625113127c91ba01a4a43de9258604f9514ee4bcb3bcf635b1f' 
  AND token = 'yVgLiLoSllesfsCjGuEdnqPKsv8zOWXYAR5SOT0Y7WM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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