SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3498d1815a0df70c4b2d205166e9237611ed2e268c283f4abdc3b7d58061aa00' 
  AND token = '6WlqZdRwUnZhoeyzsjHMoV/oRuvufyd8XrjE/HoqInk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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