SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5fa9a667036af95c5bac07dcf8850eb11ae20a487e13fb2baf1070b4f3eb881' 
  AND token = 'pcEgdz+v3WNvC3lznlNEQcgpEJm6OC3cRLKI9ZCyjpE=' 
  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"
    }
  }
}