SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '960a8de1189567744eeb14a0b5f9c5c6a4a5087436ef3a4f5015af6579212a37' 
  AND token = 'jNph/xfgNd3wBZo/Rr+mtpgeSw9Zut7+95JczG3goMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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