SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60f00b081455d2384794f0c2004d873ca072756624c8008387506e528548f5d8' 
  AND token = '/Dg20jk77WLDoW3vP5AZjm+xEggUZlwyXc6TjLTAP/Y=' 
  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"
    }
  }
}