SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be373cb1bf0c8c30adcfec33579fc6183fbc98a62a59b75ad38c6d4dbc594003' 
  AND token = 'fDh2fDduVOMX79t4DXSSm13XZceDOAeMSZZzvwkXk8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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