SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d162e93b3d51799e8543c3f8e6589b2b7e9dd92232185066ef875cfa66955c8' 
  AND token = 'RHBEGZK5ygkL60d7OSLci5+QCDhIJaFhCCtNGR/EQRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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