SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c94452fd0fc507acfbce05f57c516a17424afb40964841b60aef0eb1ea28975' 
  AND token = 'S/fDhSd26HUL+rXEpc71G6NsywbO1KQO8a84cc/xds8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}