SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2a4afea2faa742979c562278e89b6e9b4f6a76ed9c97239120cd886c1cb30c5' 
  AND token = 'bjWVxqSnhZxhfql6Q+CBEgCzGKjL6b3cD7DB8zI8cJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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