SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98ab98ad992a43518cdd47e455b5878bb816a72cbf388376dd58e4e796a0fc65' 
  AND token = 'PRcwXmCTMPN9lXTPpbbR/UuPVDxCUJC+bNXY6o9csb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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