SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '753b7f22d0ed84e27cb5d2081b95db0ccd83673ba48d2995a3666a2e26e6d7d7' 
  AND token = '8oc9K1+J9Fppj+DaJA/v+PrV9qCXu04LK6vCJhnE1ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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