SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83c4108fae8a34d1fa0905550888173d2d70891ecace0e09b52b4218c16b2432' 
  AND token = 'Ga6IUKESdquSlidLTkpkojErAvinn6wWtdEgiXtCZd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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