SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ee202d8329631cb120ead7c76bcf5f28b91032a4a84a772b6e3559b5af3c1ca' 
  AND token = 'VTyBOxIRmwtKPx8Er3GlQlcYhMFOHKYUVDzhz4INdoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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