SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee8b249107c72f7ca226774dc0717d677ca4a5b7b270804292319c14dd632673' 
  AND token = 'mdfcSIWwadJH0N8Md/raZSTgis6FKgwxCZMX2JvVjRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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