SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2177f7b8fa7f21b0f2dfba0dccff9034fb14edffe44849c83ba68013078155f' 
  AND token = 'JZSZC+2MVgluDFwBSyC+89VYqixs3lLZhHsgAdiYcrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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