SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc86472233fc96b77ea33fbe4f5a170742244db9237f3ab9bd0f5460976e8f8e' 
  AND token = 'q8PA9uCBPM23C0KwXZUMxyRn1/gTxHSLkipjCfAdTTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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