SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa535490b930d3a9ea5c8a04aedbc70b3f7a3ac745c3e85fa9954e3789c35729' 
  AND token = 'rxDlLka1VqE2+4eVPFcZg1fyM0hhAs1FpNhn5b3M9h8=' 
  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"
    }
  }
}