SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1353694f0fc933d0016ffad195956d2e232c5bf08f773e7058f4c5bbeb6fda37' 
  AND token = 'XGMRp9V//gjpWU/ZfUCZ6TAzTAuyfPg1f0glwO/LZB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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