SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73782331d87f6b597ee05359b61083381c9107b652ca63bf4819b9d1f075ab5e' 
  AND token = 'tmn+3nq/rfD8cyujGiGqgfCb6d9gyHUbCFj3dh9QuqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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