SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '192c20bfcba377b3902517875c6917e62297fe1a9e87011e6eab5ac7734f5b06' 
  AND token = 'Mn4ECnWJZdg/QIWDFtPj8wlEewewENvDxekM2VbO4Ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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