SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b940f652f051499689881cfd7b6159f4d44bd97ee0dbbc1a23ea58cb33dad09c' 
  AND token = 't5rRVPS903rgjRgBk36audSkfm313STCATJ9o2BSwwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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