SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b013d26456e5a11b8b18f99452f088a613eed79d3d4239100cecf3d2642a2954' 
  AND token = '9CLhwCpJRjeYMrBouZvDdgFlfRUKH8/J0uDOfSOprrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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