SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b39db218cd6bc5a9db7d436d4a76807b0cb4ebc824fac11de8b268d9636f6e5' 
  AND token = '2lW9YtivUhIHN6heraUt2HP89EK4t7u3XKGTzXzaySI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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