SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de40a6cee3d30c22e97753a1e30446f7eea7b3a8ac282ba55c1cd287d9660a65' 
  AND token = 'bSD84yGitmlXpI7GWxsE08p3sjCHFiCBT06cKSd8wno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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