SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d98779835fe29cb8ba060cc88306dba545d77b7da3aa989173e2676758ebb15' 
  AND token = 'ZFeeybIzdZBvek+gmBifbG4EjhLXD3YEZRqJNK6MOUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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