SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41ad2e272072f0edcbd6691cfa5e1ff5bd66d4022f28d16e97902fc852fb9c08' 
  AND token = 'vejSilDuB3QAtAo77h3Q1jfpBu1CI3lbETsRFRqklWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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