SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecd39b64b04e8123c27c1c53940ef631c070e9e8133a3d3f7b868cf31fd30b12' 
  AND token = 'cSknBbM7RlLZYp03ZupJmhIhn7njIVFrMxbimJrSBgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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