SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0283914bb0bb27e344dd89b4936c412986c637b48b55bc7878d39094ee4cf94b' 
  AND token = 'NTJnDzLtO+k1+7LVVKau3TvbYxHBqWK+OCM7TzW9XSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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