SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dc96d2963b2d2d700a233f52bc6b844d4ac060c3c26610b3c0d3abd41a4e53f' 
  AND token = 'CmqhAhRtKVcL/WKZdExupw7PgIZct1RVmdmUf3Ynffo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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