SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9751e8fba896cc53dce67e4f78a6d95a20ac164b0f1b6d561152ebbaf03f8dc6' 
  AND token = 'w78AuVjFgH6kzV3gVg+GZREA/i4ru7w9m3puPaOBS1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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