SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '261b330a919ae809c12c1d07e031a3a3f842f30fe8f79bda24ab3c0895c596bc' 
  AND token = 'Qol2O+pmoXAds8gSCTP74meP8xYQ0DB+L4lNpTrIxvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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