SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1659914a671a6f334828d9a9a1fbb72cf9caf8d27ca4906cf4458188304dd35' 
  AND token = 'hFnOnmyiVY7ZhFl/nYd6bT4wmRNoMWkYdIY6HYKG/Kk=' 
  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"
    }
  }
}