SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba389ae99067f31e3c6d1e1bff9041ce54f9a2730e1c2d8a816edab96358cba7' 
  AND token = '+pAPAbXqyTffojiCOeJmVgVltlnsLfvQpzjz1QBoVw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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