SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '161c37a660f1fa8b18cbac874e1062c6ae0099ad18c954343f9b7582f66fc0c2' 
  AND token = 'DwBOswsnNfPMvJB9QYFbl5lBO3KbiiLO3f8ov7GfE0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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