SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46230df5e46c342d1989601773bf2815a7bf79540266acf793e81e3555cfd9b3' 
  AND token = 'J9EzFqX3bVOV+Ngvun7y0VIAkFhfB/XWPMHxcrT1zcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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