SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61dcd399b421bb5df6c120823394d6b28c484e7a692ed4daef5f3439678042d2' 
  AND token = '6aqDaCjgXjSsQxmSJwO/jrHTvyscyVQ/rVZh/sy6gBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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