SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '38405f338ef23ae0237950d7d5658bf75bd355dcdc6775636103e307ffdf3a8c' 
  AND token = '5N2O/1jhC6OEpt2LEvWPGWhcUcSgKuXezjVZ8mAIT5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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