SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c174e3edaabdce7e254241ce11a3cc4f26315b41e8ff3b5d3009aa1e14c337b' 
  AND token = 'njvILQuxD3CMky8o8rYOSZYdcZIMuZG+bynxqvMNUQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}