SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb17bcecd5374bb0cf602f2bd9fcb5cb11094eab015dc1c50908f411631f1419' 
  AND token = 'rC0eJms2M8KGSY3ylp5A1VUpQsztTfxb53EaxqTecLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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