SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50171ca21a54a8d6b4c58a0dc6704f5ff371d519c35b4341973400fc9e12ab63' 
  AND token = '539QAjXF74nqIoqenW5ezR+ohI05mOhlJFX1ZFwgUSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00238

JSON explain

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