SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6334a34ca9b72829a8cda625041e9e9a583371c344f328bba82251e418fa59' 
  AND token = '2Hd3MHrtY2eHOX0jJDilhs/x4H5MArhJgXDj1upik6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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