SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '252bb162c7c8264304d896048a206ac330028d7372893a4378c835c90b53b41b' 
  AND token = 'EtF5aAcFmifDVbkQTU6Vp4skdh18Mi0sgjeAx8ksTDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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