SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c10740aabbf4d26f1d01f83a1af5af1546292d1cd939442408c47fa9995e1c2f' 
  AND token = 'VGDKqHYlDYw5Rzwj0lBRBzLuryr3zZVl/T08quTy2fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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