SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56875c84060e10b0e68c1089d1d558ac1e118db57957eed42183ff31864e5cdc' 
  AND token = 'BVZ9+qliS1qmJqA7f9k6wcIZAxuJBooe9IbRSmlID+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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