SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23c82ddc85470815532a2313d102ba033f6866ce54ec9effbf9fba209d1a857f' 
  AND token = 'Ifdhmlc8USBU4n255IhUk3eah0Fs1wnpqPbSPKMWu9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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