SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f25998330cbd17daa478b6c7b42bab4478cce8218ef32957f05ae51ee1301e8' 
  AND token = 'eRuWA3QOYWfTp30P64gCFr+1onCOWfSrA+SMGruUsdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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