SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5291b8727d8a5a3f19cc36fa3d1f3dfe96f64265b69578ef0a1d066e64a0ba8f' 
  AND token = 'sgLlazhWmjcHxuqIhhMD60khrn8H0Kqy17umWUbcTno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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