SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8197d877c01fcb50f7adbef0eab37f58d88ec957e98bafe0ea62c1e1ecad1f0' 
  AND token = 'yapVpe9jFJjRGiqCN9Fic1HByiPlbZMJyO0v/76vWIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}