SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f123027796eb517d23abb5de368453ccbfc9c50f52b7e9a07ddbf3f8a59a8619' 
  AND token = 'j6VB2IAdtgRNdxq+20LYZIng07XAvgFOeTVRjkbZlo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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