SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bcbdba0a9d57e0d7e07a2d802f8cc671a7a0377c32b22a520794202b8bd9670' 
  AND token = 'XELM5MZgzidH6QDVjAzvo5RcEc3/J/vHnQRtcwkB4LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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