SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cf9ce953a6e791866c3f99d56d6f93678dcc69a5d4c5e9a1ba0fd8766ddaa77' 
  AND token = 'd9QjYQ7iswnK6gqOXdIGDrEdIAEUw45B6I5UQTSjDWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}