SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b44b8a87cbab012c21d317a755dc2eebe89797160b44ca1d63a23d3fb1049b8' 
  AND token = 'BwtDtxP2S27kpyUmZh4/8CqdZrHr9iOWohOnGpfxg5w=' 
  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"
    }
  }
}