SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f08285ff8a41ed8de63dae0596384f8b211a16d92115b77f03ff0d742a55e561' 
  AND token = 'oWrVO5GKNqO5zdK1RhEvMhoCW43XMdlprUtiIlvVbwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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