SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ed69c265ee5abd9e517afeff2b6b3e6eaf450bf8a0de88ab97b4482185348d9' 
  AND token = 'IOIawToc/CCb8OIVXatx7ii6cUtYhgFUKtJHUGyf0Y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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