SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62747a6296c22658cff1c039ba2ccd0fa93870352ba03f0a7256c02dccd4f636' 
  AND token = '8zNynZjVhUKbirKufjjEGzjtoUnYs6TBCVd4V6ih6d0=' 
  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"
    }
  }
}