SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2021df173829a588ffe4a5399b41cb88a70bc869d234feefb5a02c75f0dc037b' 
  AND token = 'TgOKRF4SKAa56SlG8qbaSpGO3Mmzacvgg+Vmp871PPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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