SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17684ef5730b00e71f1c9a4b65d85ab2c2769d0d8d314d6c22150f6a88f63234' 
  AND token = 'hq7maUVJ5pgeM9vssQxAKX6CBhQjhApDrPLYBW6Zo/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}