SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd73d79d932ecec5de3cf277b91194cfdb1f3958dd411020d7dd27ac8a5779ef0' 
  AND token = 'KkNKyoUzPG2xPdgJ97xcU+e9noqVomOaXK4pGBs4yPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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