SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29da717bf67b90f5ab32c5b570ad916589a32232d50ba31c780a2a468938044f' 
  AND token = '4I3MPNktbG0xNZYMlEBIeM3wMGRWOvCk+lLB6ybuUmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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