SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bbd0c83bf32bcc9d04fec2171bb313bedbb057dab3e1ad90f1ff0adb7880c06' 
  AND token = 'HlikQiXQV4PVclZ6j5aUgDg/jEaTIbfiCRoxoiuAvlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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