SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8ce8901c7550676bc3e64695d36364ecbe47ee69a5c7695097fd6a410ece536' 
  AND token = 'Tazeam1Z6sLvgIzuwV+kWE6Q/XibNcMvvZ52AGtOAkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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