SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7879a3295a5aafdb4ab92fc4fa7780ce8aba3373741d1ea6f1eac6bdf42da713' 
  AND token = 'bc7ktuTlu6qm858h0JzVKUvxlzMNTkyQ2bb2tu9lc3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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