SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38dd3b93864eda5aca78437264c46e809723b88fe2ba8d0907f9fe49adee4989' 
  AND token = 'RjGuXHDCFVzisaenTcRfyJpPTd4aUPjV6qkLeuDzFfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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