SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70da9f51cceb13d9b23a620a63d8b87ebb9126246e1435d6b08c5875c6ba2f86' 
  AND token = '850lyDAKLlocHdXmT6ER1Q7bzr6G3Cku1KUpZm0OH1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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