SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8eb94b2ef03562fe4318c2eb5457584cbc17ac3f951a062d3824fea0d0d47cc' 
  AND token = 'DdfVlLNeXlVuIdfeN/SbJ5ndH3gpuouNHyfzXBwK31g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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