SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfadd858d12426bbf23fa8fbbbad38ce859c1f741846f40f9f6dee608299be96' 
  AND token = 'd3ptuwJDmp0rKUrbVX1lr/+5YDhydLsqmE08YXsHTaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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