SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bb5921b8a4d81bad66912ffb10a7bc486468d0183fa5716d0fc7a599a130785' 
  AND token = '2kfXzveOxzjkhwt7OOKFSiHPk2Jbsmo3deQOCt5jPC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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