SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c29f17cc694c85d43dfe90ddc7b52c00d6de6021e0e2d645088b6be68b094bf9' 
  AND token = '5znASu0ZRZZZbtTmWWc2TSXSAVk+zMnKN0k/zNXttV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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