SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '268d3d04a02d2c6c60f5df4f984caba58fd416d302dd3d198dc7656c86ed74c2' 
  AND token = 'YagoodC66ZaT/LQZXtHAVXfFcbX6xBnDROmcaDW8iRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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