SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d817f9701ae77799560be981cffe8af07f2acde20757deda388a7600b29cd3c' 
  AND token = 'yv9hqx/JWGKIK7LI13aoZ/VzxAn6U9GNtcSY/wzQd+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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