SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fb3dd074db31e95da45b0dee24342a3738b5061c83a0f77a5cfb118089d1fb4' 
  AND token = 'IndJY3OfqWk+lalKZJP5KNxwRe9Z5lzn6PRHmKOAH04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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