Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb23e6e40f7a7003a0bd17e4ac77a3cf6fe98242a3a78ae34be711634d6a5cd8' 
  AND token = 'kLZcubcoiQtyG4qz3EuUYMQgCJm0PT5j/VFvz0dmVDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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