SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '561d53a30b3f0c9f860c024b74862ca42869d5921e8a3550d3f891f4ee127818' 
  AND token = 'j+m/Yr4pdYdNlsShqOT6zbNRzr9SLvZsBF7QfRzdV90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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