SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e0b023072d42b4731e7f377fcd484599303e2aadf445edf846563cba78a8e0a2' 
  AND token = '9a+o7YHHesoyFTo6EJlv+Zg2R/vswpEWHBfgvCguEuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}