SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934842d904bb84255cb64fae5c97476c798952e9c1961aeff4159dff963cb8ca' 
  AND token = 'KTOq1HJdhQIkrzCL1bK7Z0oBYZwXNdYMmmow+o/D7M8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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