SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec298435eb907bda11d28e677afa5596c3c743ea677e02c0267aa30189502775' 
  AND token = 'qEmRvcsBE8aShBb+tHXAG76jnhthWWPRynrAw1MVglM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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