SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '72d5ac793832eb6652e2a7b3bfb56a23f89c9a4afa351be482544c3393236ee9' 
  AND token = 'DpAg2093+LkgXnX8OsM4JahB0OVZ6zw3gRZLBH14Ml0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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