SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb364399db93c4a2cb890e66430eccd690fa6c9fabf15543a50ec5bebceeddc' 
  AND token = '6LVN8CNxA0oc2KPYMcUTcqiWAcCxd8xQmePiLrkoKRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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